Naga Siren
* Timbersaw's innate durability provided by 
Reactive Armor is very hard to deal with as Naga Siren as she mostly relies on sustained damage rather than burst damage unless if she is played as Nuker.
* Timbersaw's high pure damage and low-cooldown area-of-effect nukes which are 
Whirling Death, 
Timber Chain, 
Chakram and 
Flamethrower from 
Aghanim's Shard can also destroy Naga Siren's illusions very fast.
* Timbersaw is a common 
Lotus Orb wielder which allows him to reflect 
Ensnare back at Naga SIren.
Primal Beast
* The percentage-based primary-attribute reduction effect of Whirling Death can be devastating for Pudge due to his high strength gain through Flesh Heap.
* Reactive Armor's health regeneration and common itemization for magic resistance and durability makes Timbersaw a poor target for Pudge.
* Timber Chain's high mobility makes it difficult for Pudge to hook or deal much Rot damage to Timbersaw.
Naga Siren
* Heroes who depends on illusions and summons: 
Naga Siren, 
Arc Warden, 
Broodmother will struggle against Great Cleave.
Primal Beast
* Generally heroes who don't rely on magical damage, such as 
Sven, 
Phantom Assassin, and 
Outworld Destroyer, as they can practically ignore Flesh Heap's damage block.
Naga Siren
* Heroes that heavily depend on illusions or summons, (Naga Siren, 
Terrorblade, 
Phantom Lancer, 
Lycan,...) are vulnerable to Sleight of Fist and even more so if Ember Spirit has 
Battle Fury.
Primal Beast
* Heroes with a high degree of mobility and invisibility are hard to catch with Meat Hook: 
Ember Spirit, 
Riki, 
Clinkz, 
Queen of Pain.
Naga Siren
* All of Leshrac's abilities, especially 
Pulse Nova, can easily deal with Naga Siren's illusions.
* 
Aghanim's Scepter gives Leshrac access to 
Nihilism ability, that allows him to turn himself along with Naga Siren and her illusions to turn ethereal. And to make things worse, Nihilism can slow Naga Siren and her illusions, make them more vulnerable to magical damage and unable to fight back while Leshrac moves faster and does not take increased magical damage for it's duration.
Naga Siren
* Many stacks of 
Sticky Napalm, combined with 
Flamebreak and 
Firefly, allows Batrider to destroy illusions from 
Mirror Image.
* If Batrider can manage to destroy all illusions from Naga Siren, he will be able to use 
Flaming Lasso on the real one, and will be able to drag her toward his team, potentially preventing Naga Siren from escaping with 
Song of the Siren.
Additional:
* Many stacks of Sticky Napalm, combined with Flamebreak and Firefly, allows Batrider to destroy illusions from Mirror Image.
* If Batrider can manage to destroy all illusions from Naga Siren, he will be able to use Flaming Lasso on the real one, and will be able to drag her toward his team, potentially preventing Naga Siren from escaping with Song of the Siren.
Primal Beast
* If Meat Hook is used before 
Leap, Mirana may be able to escape Pudge's grasp by leaping to safety.
* The invisibility from 
Moonlight Shadow gives a degree of mobility, which can make Mirana or her teammates difficult targets to hook.
* 
Sacred Arrow can be used to cancel Dismember from long distances.
Primal Beast
* Pudge is particularly susceptible to Bristleback's 
Viscous Nasal Goo and 
Quill Spray due to his naturally low armor and poor agility gain.
* Bristleback, in combination with his strength gain, high health, common itemization for magic resistance and damage reduction from 
Bristleback makes him a poor target for Pudge.
Naga Siren
* Centaur's 
Retaliate will harm all attacking enemies, which will allow Centaur Warrunner to see which is the real Naga Siren.
* A well timed 
Hoof Stomp followed by 
Double Edge will clear all Naga's illusions and prevent Naga Siren from escaping with Song of the Siren.
Primal Beast
* If Meat Hook is used before 
Blink, Anti-Mage may be able to escape Pudge's grasp by blinking to safety.
* 
Counterspell grants Anti-Mage a large degree of magic resistance, a damage type Pudge is highly reliant on to secure kills. This makes Anti-Mage a bad target for Pudge. The active can also block Dismember if timed correctly.
* 
Mana Break can quickly drain Pudge's low supply of mana, which may render Meat Hook and Dismember unusable.
Naga Siren
* Avalanche and Toss combo makes short work of Mirror Image's illusions.
* Tiny's cleave with Tree Grab and area of effect damage with Tree Volley will easily wipe out illusions.
Naga Siren
* Dawnbreaker can easily clear waves of Naga Siren's illusions from Mirror Image with 
Starbreaker, 
Celestial Hammer and 
Solar Guardian.
* Aghanim's Shard upgraded Starbreaker will allow Dawnbreaker to dispel Ensnare and freely attack Naga Siren during Song of the Siren when combined with 
Black King Bar, a common item on Dawnbreaker.
* Solar Guardian allows Dawnbreaker to counter any pushing attempts of Naga Siren and rejoin her team with Solar Guardian when they require it. Aghanim's Scepter upgraded Solar Guardian can also give Dawnbreaker's allies evasion while Dawnbreaker is airborne for it's duration, as Naga Siren mainly relies on direct attacks in order to deal damage. Solar Guardian can also be used after Naga Siren uses Song of the Siren near her allies to either escape from or counter-initiate against them.
Additional:
* Dawnbreaker can easily clear waves of Naga Siren's illusions from Mirror Image with Starbreaker, Celestial Hammer and Solar Guardian.
* Aghanim's Shard upgraded Starbreaker will allow Dawnbreaker to dispel Ensnare and freely attack Naga Siren during Song of the Siren when combined with Black King Bar, a common item on Dawnbreaker.
* Solar Guardian allows Dawnbreaker to counter any attempts of Naga Siren and rejoin her team with Solar Guardian when they require it. Aghanim's Scepter upgraded Solar Guardian can also give Dawnbreaker's allies evasion while Dawnbreaker is airborne for it's duration, as Naga Siren mainly relies on direct attacks in order to deal damage.
Primal Beast
* 
Kraken Shell can dispel Dismember after reaching a certain threshold of damage.
* Tidehunter's naturally high health, strength gain, and common itemization for survivability through magic resistance makes Tidehunter a poor target.
Primal Beast
* 
Doom disables the toggling of Rot and, if cast at the right time, may leave Pudge with a potentially lethal health drain.
* Doom's naturally high health, strength gain and damage output makes him a poor target for Pudge.
* The damage of Doom's 
Infernal Blade scales with the target's maximum health, which is particularly effective against Pudge due to his naturally high health and further health granted by stacks of Flesh Heap.
Naga Siren
* 
Mortimer Kisses can make quick work of Naga Siren's illusions.
* 
Scatterblast and 
Firesnap Cookie's AoE damage are also decent ways to deal with Naga's illusions.
Naga Siren
* Mirror Image's illusions increase Echo Slam's damage.
Additional:
* Earthshaker's strong AoE abilities can clear Naga Siren's illusions, or at least make it easier to distinguish the real one by the damage they take.
* 
Echo Slam deals more damage against more enemies, which can be devestating against Naga Siren and her illusions.
Primal Beast
* 
Shukuchi grants Weaver invisibility and a high degree of mobility for a short time, which can make him a difficult target to hook.
* 
The Swarm beetles are difficult for Pudge to remove, due to his low base attack time and poor agility. Additionally, it can be used to can scout out Pudge's location.
* Should an ally get snagged by Meat Hook, Weaver can use Aghanim's Scepter upgraded 
Time Lapse on them to send them back to where they were before hooked, even if Pudge has already started to Dismember them.
Primal Beast
* Oracle can negate and shut down Primal Beast simply with Fate's Edict, especially in the early game, as a majority of his damage-dealing spells are magic.
* Oracle can interrupt Primal Beast's 
Onslaught charge with a well-timed Fortune's End.
* Primal Beast's lethal burst damage combos can be further stalled with False Promise; combined with Fate's Edict and regen from Purifying Flames, Oracle can even completely negate Primal Beast's offense.
Naga Siren
* Jakiro's damage over time abilities can clear Naga Siren's illusions and can hurt real Naga Siren even for the duration of Song of the Siren.
* Naga Siren is not a hero that likes to go for Black King Bar, and that makes her very vulnerable to Jakiro's damage over time in every phase of the game.
Additional:
* Jakiro's damage over time abilities can clear Naga Siren's illusions and can hurt real Naga Siren even for the duration of Song of the Siren.
* Since Naga Siren is a hero who barely goes for Black King Bar, this can make her very vulnerable to Jakiro's damage over time in every phase of the game.
Naga Siren
* 
Waveform clear Mirror Image illusions from Naga Siren. And though Ensnare can prevent Morphling from using Waveform to escape, he can easily dispel it with 
Manta Style, a common item on Morphling.
* 
Morph allows Morphling to copy Naga Siren's abilities and combine them with Manta Style, a commong item for Morphling, to destroy Naga Siren's illusions. Aghanim's Scepter upgraded Morph also allows Morphling to create a strong illusion of Naga Siren that can do the same and which can also allow Morphling to close the gap on Naga Siren.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, 
Magnus, 
Dragon Knight, 
Luna, 
Medusa, 
Templar Assassin, 
Gyrocopter, 
Muerta.
Naga Siren
* Heroes with summons and illusions can find themselves easily bested by Lina, like Broodmother, 
Nature's Prophet, 
Chen, Terrorblade, Naga Siren, 
Visage, 
Wraith King, Lycan, Phantom Lancer, 
Shadow Shaman.
Naga Siren
* As long as Windranger is able to identify the real hero among the illusions, heroes relying on them can be easily tagged with Focus Fire: 
Chaos Knight, Terrorblade, Phantom Lancer, Naga Siren.
Naga Siren
* Heroes who rely on illusions will see them destroyed easily by Overwhelming Odds: Phantom Lancer, Chaos Knight, Terrorblade, Naga Siren
Primal Beast
* Legion Commander can use 
Press the Attack on an ally to dispel Dismember. The bonus health regeneration also partially counters the damage of Rot
* 
Duel can be used on Pudge whilst Rot is active, disabling toggling which may result in a lethal health drain that leaves Legion Commander with a successful duel.
Naga Siren
* Song of the Siren lasts long enough to prevent a successful Duel (but only if Naga wasn't the target).
Naga Siren
* Because of his massive AoE damage, Sand King is very effective against illusion heroes: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren.
Naga Siren
* 
Lion may upgrade 
Mana Drain, 
Hex and 
Finger of Death through Talent Tree and Aghanim's itens to make them affect secondary targets or turn them into AoE abilities. This can make things difficult for heroes like Phantom Lancer, Naga Siren and Terrorblade, who rely on illusion armies.
Additional:
* Both Hex and Mana Drain destroy Naga Siren's illusions in an instant, making it hard for her to teamfight or push against a team with Lion. If Lion chooses the AoE effect talent for Hex or the shard for multi-target Mana Drain, it can negate her pushing potential entirely.
* 
Earth Spike is an AoE disable with good damage. If used well, it can help distinguish the true Naga Siren by the damage they take (illusions take more damage).
Primal Beast
* Anti-Tank heroes like: 
Razor, 
Necrophos, 
Undying.
Primal Beast
* Heroes with a high degree of mobility and invisibility are hard to catch with Meat Hook: Ember Spirit, Riki, Clinkz, Queen of Pain.
Naga Siren
* Heroes with long cast animations can be continuously interrupted by Battery Assault: 
Centaur Warrunner, 
Jakiro, 
Leshrac, Naga Siren, 
Underlord.
Primal Beast
* Anti-Tank heroes like: Razor, Necrophos, Undying.
Naga Siren
* Naga Siren's Song of the Siren may be useful but Poof will destroy all of her illusions.
Primal Beast
* Any heroes that naturally buy 
Diffusal Blade like Phantom Lancer or have a mana break talent is a big issue for Pudge because of his low mana pool.
Naga Siren
* Heroes who are reliant on illusions or summons: Chaos Knight, Broodmother, Naga Siren.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: 
Spirit Breaker, 
Bloodseeker, 
Witch Doctor.
Naga Siren
* 
Keeper of the Light can stall pushes with 
Illuminate. This makes him strong against pushing heroes: Terrorblade Naga siren Nature's Prophet and 
Anti-Mage
Primal Beast
* 
Corrosive Haze reveals Pudge's location, making it hard for him to use Meat Hook from the fog of war on Slardar's teammates or Slardar himself.
* 
Slithereen Crush interrupts Pudge while he is using Dismember.
* 
Guardian Sprint allows Slardar to avoid Meat Hook.
Naga Siren
* Illusion heroes like the aforementioned Phantom Lancer or Naga Siren, or heroes that tend to buy Manta Style, like Luna or 
Juggernaut, will give Slardar a hard time, as his damage is single-targeted.
Naga Siren
* Axe will destroy her illusions by proccing 
Counter Helix more often due to him being hit by more attacks.
Primal Beast
* Long lockdown is a great way to deal with Axe to prevent Berserker's Call from being used, heroes such as 
Legion Commander, 
Beastmaster and 
Primal Beast are good examples of this.
Primal Beast
* 
Track can easily keep vision on Pudge, making it very hard for him to hook Bounty Hunter or his teammates from the fog of war.
* 
Shuriken Toss cancels Dismember from great range.
Naga Siren
* Naga Siren with Mirror Image
* Heroes that can remove the Track debuff with their skills:
* 
Abaddon with 
Aphotic Shield and 
Borrowed Time
* 
Huskar with 
Life Break
* Juggernaut with 
Blade Fury
* Legion Commander with Press the Attack
* 
Lifestealer with 
Rage and 
Infest
* Naga Siren with Mirror Image
* 
Omniknight with 
Heavenly Grace
* 
Oracle with 
Fortune's End and 
False Promise
* Phantom Lancer with 
Doppelganger
* 
Slark with 
Dark Pact
* 
Ursa with 
Enrage
* 
Weaver with Time Lapse
* 
Tidehunter with Kraken Shell when damage received reaches the threshold.
Additional:
* Bounty Hunter is a single target damage dealer, so he will not fare well against Naga Siren. Even though Bounty Hunter can use Track on her, Mirror Image will dispel the effect. Ensnare also reveals invisible units while they're rooted, putting Bounty Hunter at a disadvantage.
Primal Beast
* Unlike any other illusion heroes, Chaos Knight is the worst target for Pudge to hook as it will definitely backfire him.
* 
Phantasm are significantly tankier than most illusion and deal full damage, which will quickly kill Pudge due to his low armor.
* it becomes worse if pudge is affected with 
Reality Rift, which reduces his already abysmal base armor even lower.
* Low movement speed and low mobility means Pudge will struggle to escape or outrun Chaos Knight in most cases.
Naga Siren
* Illusion-based and multi-unit heroes can take advantage of Chaos Knight's lack of area damage: Naga Siren, Phantom Lancer, Broodmother
Naga Siren
* 
Flak Cannon and 
Call Down can easily clear Naga Siren's illusions.
Primal Beast
* Abilities that deal low damage with high amounts of instances are irrelevant against Pudge during Flesh Heap's active: Gyrocopter's 
Rocket Barrage and 
Dark Seer's 
Ion Shell are just a couple examples.
Primal Beast
* The lifesteal of 
Feast scales accordingly to the max health of its target, which is effective against Pudge due to his high health and further health granted by stacks of Flesh Heap.
* Lifestealer can activate Rage to be spell immune, making Rot deal no damage.
* Pudge's plentiful health makes him an ideal target for Lifestealer's Aghanim's Shard ability, 
Open Wounds.
Naga Siren
* Heroes with illusions: Chaos Knight, Naga Siren, Phantom Lancer, Terrorblade
Naga Siren
* Luna's 
Moon Glaives and 
Lunar Blessing can clear waves of Naga Siren's illusions from Mirror Image.
* Once Naga Siren's illusions are cleared with Aghanim's Shard upgraded Moon Glaives, 
Eclipse can often finish off Naga Siren before she can escape with Song of the Siren.
* A well-timed Aghanim's Scepter upgraded Eclipse combined with 0.25 Eclipse Lucent Ministun talent can be casted at long range and allow Luna to burst down Naga Siren faster and repetively stun Naga Siren, preventing her from escaping with Song of the Siren and 
Town Portal Scroll without getting caught in it's range.
* Luna is a natural Black King Bar wielder unlike Naga Siren who barely goes for it, which allows Luna to freely attack Naga Siren during Song of the Siren and potentially get rid of the most of the damage and crowd-control from Naga Siren.
Additional:
* Luna's Moon Glaives and Lunar Blessing can clear waves of Naga Siren's illusions from Mirror Image, especially when combined with 
Gleipnir and Manta Style. Aghanim's Shard upgraded Moon Glaives can also be used to destroy Naga Siren's illusions and damage the real Naga Siren if they are too close to Luna while also reducing any damage Naga Siren inflicts on Luna for their duration.
* Once Naga Siren's illusions are cleared, Eclipse can often finish off Naga Siren before she can escape with Song of the Siren.
* A well-timed Aghanim's Scepter upgraded Eclipse combined with 0.25 Eclipse Lucent Ministun talent can be casted at long range and allow Luna to burst down Naga Siren faster and repetively stun Naga Siren, preventing her from escaping with Song of the Siren and Town Portal Scroll without getting caught in it's range.
* Luna is a natural Black King Bar wielder unlike Naga Siren who barely goes for it, which allows Luna to freely attack Naga Siren during Song of the Siren and potentially get rid of the most of the damage and crowd-control from Naga Siren.
Naga Siren
* Heroes that create illusions: 
Spectre, 
Shadow Demon, Phantom Lancer, Naga Siren, Chaos Knight, Terrorblade) or bring other units into the fight (such as Nature's Prophet, 
Lone Druid, Chen, 
Enchantress, 
Meepo and Arc Warden) can cause Eclipse to strike the illusions/summons unintentionally. However, in many cases Moon Glaives can resolve this issue and eliminate them before activating Eclipse, but that will require lots of farming for right-click items.
Naga Siren
* Medusa's 
Split Shot and 
Mystic Snake combined with 
Mjollnir, a common item for Medusa, will whittle down all of Naga Siren's illusions, including Naga Siren herself.
* Medusa's 
Stone Gaze can disable Naga Siren even for the duration of Song of the Siren and even if Naga Siren is spell immune, discouraging Naga Siren from even trying to use Song of the Siren to save herself or counter-initiate against Medusa.
Additional:
* Medusa's Split Shot and Mystic Snake combined with Mjollnir, a common item for Medusa, will whittle down all of Naga Siren's illusions, including Naga Siren herself.
* Medusa's Stone Gaze can disable Naga Siren even for the duration of Song of the Siren and even if Naga Siren is spell immune, discouraging Naga Siren from even trying to use Song of the Siren to save herself or counter-initiate against Medusa.
Naga Siren
* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, Naga Siren, Terrorblade, Juggernaut, Spectre, Slark.
Primal Beast
* 
Heartstopper Aura is effective against high health heroes, and Pudge is no exception. Coupled with his self-damage from Rot, being around Heartstopper Aura could prove risky for Pudge.
* Regardless of how much health Pudge gains through Flesh Heap, 
Reaper's Scythe will often kill Pudge should his health fall below 40%, making Necrophos an ideal counter versus Pudge.
Naga Siren
* Illusions make it difficult for Necrophos to target his Reaper's Scythe correctly, thus giving illusion heroes like Chaos Knight or Naga Siren an edge against Necrophos.
Primal Beast
* 
Impale and 
Spiked Carapace can be used to cancel Dismember easily, and can even do so when Pudge uses it on Nyx Assassin, if timed correctly.
Naga Siren
* Nyx Assassin's skillset is mostly single-targeted, therefore he will have difficulties against heroes with illusions and summons: Naga Siren, Broodmother, Lycan, Visage, Phantom Lancer. And to make things worse, Nyx Asassin is not a common Battle Fury, 
Maelstrom, Mjollnir, Gleipnir or 
Radiance wielder to counter this problem.
Primal Beast
* Dark Pact dispels Dismember if timed correctly.
* 
Pounce allows Slark to escape Pudge's Rot once Dismember is over, and allows him to dodge hooks.
* 
Shadow Dance hides Slark and grants him a high degree of mobility, which can make him a difficult target to hook and also protects him from Pudge's Dismember (including allies with an Aghanim's Shard).
Naga Siren
* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, 
Faceless Void, 
Storm Spirit.
Naga Siren
* 
Atrophy Aura makes it hard or Naga Siren to farm on lane and damage Underlord with 
Rip Tide in teamfights. And her only way to counter this is by playing Nuker role.
* 
Firestorm is very useful for clearing Naga Siren's illusions from Mirror Image and Manta Style.
* However, Naga Siren can catch Underlord and his team unprepared with Song of the Siren if he chooses to use 
Fiend's Gate to get to a designated point of the map. Naga Siren can also prevent escaping with Fiend's Gate with Ensnare and 
Reel In from Aghanim's Scepter.
Additional:
* Atrophy Aura makes it hard or Naga Siren to farm on lane and damage Underlord with Rip Tide in teamfights. And her only way to counter this is by playing Nuker role.
* Firestorm is very useful for clearing Naga Siren's illusions from Mirror Image and Manta Style.
* However, Naga Siren can catch Underlord and his team unprepared with Song of the Siren if he chooses to use Fiend's Gate to get to a designated point of the map. Naga Siren can also prevent escaping with Fiend's Gate with Ensnare and Reel In from Aghanim's Scepter.
Naga Siren
* Heroes with strong area-of-effect damaging and/or disabling abilities will be able to intercept Underlord and his team when they exit from Fiend's Gate: Luna's Aghanim's Scepter upgraded Eclipse, 
Dawnbreaker's Solar Guardian, 
Axe's 
Berserker's Call, 
Mars's 
Arena of Blood, Jakiro's 
Macropyre, 
Dual Breath and 
Ice Path, Naga Siren's Song of the Siren, Razor's 
Eye of the Storm and 
Plasma Field, 
Lina's 
Light Strike Array, Broodmother's 
Spinner's Snare from Aghanim's Scepter, 
Elder Titan's 
Earth Splitter and 
Echo Stomp, 
Alchemist's 
Unstable Concoction and 
Acid Spray, Queen of Pain's 
Sonic Wave, Dark Seer's 
Wall of Replica and 
Vacuum, 
Venomancer's 
Noxious Plague and 
Poison Nova from Aghanim's Scepter, Oracle's Fortune's End and 
Rain of Destiny from Aghanim's Shard, Bloodseeker's 
Blood Rite, 
Enigma's 
Black Hole and 
Midnight Pulse, 
Shadow Fiend's 
Requiem of Souls, 
Batrider's Aghanim's Scepter upgraded Flaming Lasso, Firefly, Flamebreak and Sticky Napalm, 
Ancient Apparition's 
Ice Blast, 
Sand King's 
Epicenter, 
Sand Storm and 
Burrowstrike, Gyrocopter's Call Down, Ember Spirit's 
Sleight of Fist, 
Death Prophet's 
Exorcism and 
Silence, 
Monkey King's 
Wukong's Command, 
Crystal Maiden's 
Freezing Field, Muerta's 
The Calling, Medusa's Stone Gaze, 
Zeus's 
Nimbus from Aghanim's Scepter. 
Dark Willow's 
Bramble Maze, 
Pangolier's 
Swashbuckle, 
Grimstroke's 
Soulbind, 
Ink Swell and 
Stroke of Fate, 
Earthshaker's Echo Slam and 
Fissure, 
Puck's 
Dream Coil and 
Waning Rift, 
Winter Wyvern's 
Winter's Curse, Magnus's 
Reverse Polarity.
Naga Siren
* Mirror Image can dispel Frostbite. A similar effect can be achieved with Manta Style, a core item on Naga Siren.
* Song of the Siren can stop Freezing Field regardless of any kind of invisibility as well as allow Naga Siren's team to quickly close the gap on Crystal Maiden.
* With Aghanim's Scepter, Naga Siren can get access to Reel In ability, which can allow her to pull Crystal Maiden toward herself and her team and cancel Freezing Field even through Black King Bar.
Additional:
* Mirror Image can dispel Frostbite.
* Song of the Siren can stop Freezing Field regardless of any kind of invisibility as well as allow Naga Siren's team to quickly close the gap on Crystal Maiden.
* Ensnare allows Naga Siren and her team to quickly catch up with Crystal Maiden and kill her.
* With Aghanim's Scepter, Naga Siren can get access to 
Reel In ability , which can allow her to pull Crystal Maiden toward herself and her team and cancel Freezing Field even through Black King Bar.
Primal Beast
* Meat Hook can cancel Freezing Field, even if Crystal Maiden has 
Glimmer Cape.
* She is also slow and fragile, making her a good target for ganking.
Naga Siren
* Ensnare with her attacks allows Naga Siren to gank Sniper easily.
* Rip Tide removes Sniper's very little armor.
Primal Beast
* Heroes who have high health are a problem for Sniper because he likes to attack the closest target and sit at the back, much like a Terrorblade so when that hero doesn't die; he's forced to show his position for a very long time: Centaur Warrunner, Legion Commander, Primal Beast.
Additional:
* Sniper has a low health pool and strength gain, making him vulnerable to Pudge's magical and pure damage.
* Sniper usually likes to deal damage away from the fight, and Meat Hook is capable of bringing him to the front lines.
* 
Assassinate won't do much damage against Pudge because of his high strength gain and the strength bonuses from Flesh Heap.
* 
Shrapnel will be mostly blocked by Flesh Heap's active.
Naga Siren
* Illusion heroes, such as Naga Siren, Phantom Lancer, Chaos Knight, Terrorblade will become strong against Tinker in the late game. Without Aghanim's Scepter Tinker is forced to defensively disarm heroes with Laser, leaving illusions free to deal physical damage which Tinker's low armor makes highly effective. In addition, Mjollnir or Battle Fury, two common pickups against illusion heroes, don't work well on Tinker at all.
Primal Beast
* Meat Hook can be used to pull Tinker to Pudge while he is hiding in the trees, and a follow up with Dismember and Rot can lead to a valuable kill, as Tinker doesn't buy many survivability items.
* Flesh Heap makes it hard for Tinker to deal serious damage.
Naga Siren
* Naga Siren can very easily dispel the 
Reflection with Mirror Image. And Besides Reflection that can be used to detect real Naga Siren, Terrorblade has no other ways to deal with Naga Siren's illusions. And what's worse is that Naga Siren can much easily detect the real Terrorblade due to 
Conjure Image having illusions having different colors. In addition, Terroblade is not a common Battle Fury nor Mjollnir wielder to counter this problem.
* Aghanim's Scepter upgraded Ensnare will allow Naga Siren to root Terrorblade even ithrough Black King Bar. And with Aghanim's Scepter, Naga Siren can get access to Reel In ability, which can allow her to pull Terrorblade toward herself and her team and away from his illusions, even through Black King Bar.
* Naga Siren can rapidly damage Terrorrblade and weaken Terrorblade's armor with Rip Tide, which combined with Terrorblade's low health and strength gain can almost completely discourage Terrorblade from even being present in teamfights. Rip Tide can also weaken armor of Terrorblade's illusions and damage them.
* Song of the Siren can be used to save an ally whom Terrorblade has used 
Sunder under the condition Naga Siren is quick enough to do it. And since Terrorblade has no "real" burst damage potential outside from Sunder, Naga Siren will usually have plenty of time to save an allied hero on which Sunder was used. Aghanim's Shard upgraded Song of the Siren can also heal her allies around her for it's duration, which allows Naga Siren to nullify effects of Sunder.
* However, Naga Siren's lack of burst damage can make it difficult for her to burst down Terrorblade before he can use Sunder unless Naga Siren has either Black King Bar or 
Linken's Sphere to protect herself against it or if she is played as Nuker.
Additional:
* Naga Siren can very easily dispel the Reflection with Mirror Image. And Besides Reflection that can be used to detect real Naga Siren, Terrorblade has no other ways to deal with Naga Siren's illusions. And what's worse is that Naga Siren can much easily detect the real Terrorblade due to Conjure Image having illusions having different colors. In addition, Terroblade is not a common Battle Fury nor Mjollnir wielder to counter this problem.
* Aghanim's Scepter upgraded Ensnare will allow Naga Siren to root Terrorblade even through Black King Bar. And with Aghanim's Scepter, Naga Siren can get access to Reel In ability, which can allow her to pull Terrorblade toward herself and her team and away from his illusions, even through Black King Bar.
* Naga Siren can rapidly damage Terrorrblade and weaken Terrorblade's armor with Rip Tide, which combined with Terrorblade's low health and strength gain can almost completely discourage Terrorblade from even being present in teamfights. Rip Tide can also weaken armor of Terrorblade's illusions and damage them.
* Song of the Siren can be used to save an ally whom Terrorblade has used Sunder under the condition Naga Siren is quick enough to do it. And since Terrorblade has no "real" burst damage potential outside from Sunder, Naga Siren will usually have plenty of time to save an allied hero on which Sunder was used. Aghanim's Shard upgraded Song of the Siren can also heal her allies around her for it's duration, which allows Naga Siren to nullify effects of Sunder.
* However, Naga Siren's lack of burst damage can make it difficult for her to burst down Terrorblade before he can use Sunder unless Naga Siren has either Black King Bar or Linken's Sphere to protect herself against it or if she is played as Nuker.
Primal Beast
* Heroes with abilities that can lock down Terrorblade and prevent him from using Sunder: 
Bane, Batrider, Earthshaker, Elder Titan, Faceless Void, 
Invoker, Legion Commander, Mars, Primal Beast, Riki, Shadow Shaman, 
Silencer, 
Vengeful Spirit, 
Void Spirit.
Naga Siren
* Heroes with illusions and summons can swarm and overwhelm Bane, who has no area abilities to deal with them outside from Aghanim's Shard upgraded 
Brain Sap: Broodmother, Chaos Knight, Naga Siren, Nature's Prophet, Phantom Lancer, Terrorblade, Visage, 
Warlock, Wraith King.
Primal Beast
* Heroes that have a channeled ability that can be interrupted by Meat Hook: Shadow Shaman, Witch Doctor, Enigma, Bane.
Naga Siren
* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.
Primal Beast
* Heroes who recklessly jump on Pudge with their gap-closing abilities will be easy targets for Pudge's Meat Hook and Dismember Combo: Phantom Assassin, Faceless Void, Queen of Pain etc.
Primal Beast
* Generally heroes who don't rely on magical damage, such as Sven, Phantom Assassin, and Outworld Destroyer, as they can practically ignore Flesh Heap's damage block.
Naga Siren
* Heroes with illusions and summons can be hard for Phantom Assassin to deal with, as she lacks any AoE abilities to deal with them without items: Broodmother, Phantom Lancer, Chaos Knight, Lycan, Naga Siren, Shadow Shaman, Visage, Nature's Prophet, Terrorblade, Warlock, Wraith King.
Primal Beast
* If Phantom Assassin jumps on Pudge first with 
Phantom Strike, she will be a very easy target for Pudge's 
Meat Hook and 
Dismember combo.
* Even though it can deal damage based on Pudge's max health, 
Fan of Knives from Aghanim's Shard cannot disable Pudge's 
Flesh Heap as Flesh Heap is one of the few passive abilities that cannot be disabled by break.
* Both Meat Hook and Dismember ignore spell immunity which allows Pudge to disable Phantom Assassin even while she has Black King Bar active.
* Pudge occassionally buys armor items like 
Blade Mail, which in combination with many stacks from Flesh Heap can make Phantom Assassin have little effect against Pudge.
Naga Siren
* Lycan is a hero focused entirely on single target physical damage and lacks disables or AoE damage. Due to this, he will have difficulties dealing with illusions or Naga Siren's Ensnare.
Naga Siren
* Although Naga Siren relies mostly on physical damage, Song of the Siren can be used to time out 
Guardian Angel, giving Naga Siren's team an easy opportunity to counter-initiate.
* Radiance allows it's owner to deal magical damage to multiple enemy heroes at once, and since Naga Siren often buys it, Guardian Angel is not a very good ability for protection against Naga Siren.
* Likewise, Nuker build Naga Siren (which primarly consists of items such as Radiance, 
Ethereal Blade, 
Dagon and 
Veil of Discord) can render Guardian Angel useless. Although Nuker is not a role Naga Siren should be playing.
Additional:
* Even though Naga Siren relies on direct attacks to deal damage for most of the time, Song of the Siren allows her to easily waste Guardian Angel.
* Ensnare fully works on targets affected with Heavenly Grace. However, Ensnare is dispellable with any dispel, and so can be dispelled by Heavenly Grace.
* As an agility hero that relies on illusions, Naga Siren is one of the most natural Diffusal Blade carriers, the bane of every hero with a small mana pool. Naga Siren can also buy items that deal magical damage like Radiance, Dagon, Ethereal Blade, 
Revenant's Brooch, Veil of Discord and Gleipnir to attack Omniknight's allies protected with Guardian Angel.
Primal Beast
* Pudge's Dismember stops Spectre from escaping with 
Haunt.
* He can easily tank the damage reflected by 
Dispersion due to his high strength and the healing from Dismember.
* Should Spectre try to get away through the trees or over a cliff with 
Spectral Dagger, Pudge can hook her back.
* Spectre takes a long time to become powerful, and Pudge can ruin her early game with ganks.
Naga Siren
* Song of the Siren stops Arc Warden from acting and allows Naga Siren's team to close in on him, past his 
Magnetic Field.
* Mirror Image dispels 
Flux. The illusions created from it also disable the slow from Flux if Arc Warden casts it after Mirror Image.
* Arc Warden's playstyle heavily favors split-pushing, which Naga Siren can compete against with her illusions.
Additional:
* Naga Siren's illusions from Mirror Image can depush the lanes pushed by the Tempest Double, relieving the pressure.
* Mirror Image can dispel Flux, and the illusions can stop Flux from working to it's full power.
Naga Siren
* Ensnare and Song of the Siren can be used to cancel both, Tether and Relocate and to close the distance on Io.
* Rip Tide combined with illusions from Mirror Image often finish off Io before he can save himself.
* Spirit's weak area-of-effect makes it a bad tool to deal with Naga Siren's illusions from Mirror Image.
* Once Naga Siren buys Aghanim's Scepter, she can gain access to Reel In, which not only allows her to cancel both, Tether and Relocate, but also to pull Io to herself and her team while he is affected with Ensnare, similarly to Batrider's Flaming Lasso.
* Aghanim's Shard upgraded Song of the Siren can also heal the hero Io and his tethered targed try to gank.
Additional:
* Ensnare and Song of the Siren can be used to cancel both, 
Tether and 
Relocate and to close the distance on Io.
* Rip Tide combined with illusions from Mirror Image often finish off Io before he can save himself with Tether or Relocate.
* 
Spirits's weak area-of-effect makes it a bad tool to deal with Naga Siren's illusions from Mirror Image.
* Once Naga Siren buys Aghanim's Scepter, she can gain access to Reel In, which not only allows her to cancel both, Tether and Relocate, but also to pull Io to herself and her team while he is affected with Ensnare, similarly to Batrider's Flaming Lasso.
* Aghanim's Shard upgraded Song of the Siren can also heal the hero Io and his Tethered targed try to gank.
Naga Siren
* Mirror Image can cause Huskar to Life Break the wrong target.
* Rip Tide reduces Huskar's already low armor.
* Song of the Siren allows teams to recover from Huskar's initiation, as well as the damage over time from Burning Spears.
Naga Siren
* Unless Lone Druid purchases a Black King Bar for his Spirit Bear, Ensnare will easily kite the Spirit Bear.
* Song of the Siren allows Naga Siren and her team to completely bypass the Spirit Bear and hunt for the Lone Druid himself when starting a fight.
* Lone Druid's lack of innate AoE capabilities mean that Naga Siren's illusions have no problem against him.
Naga Siren
* Illusion or summon-based heroes can be a problem to Viper due to his lack of AoE damage: Naga Siren, Phantom Lancer, Beastmaster
Additional:
* Naga Siren can easily disjoint, and dispel 
Corrosive Skin with Mirror Image.
* Since Viper is mostly a single-target hero, he will not have almost any chance against Naga Siren because she is an illusion based hero.
* Viper has no burst damage, so Naga Siren will have plenty of time to use Aghanim's Shard upgraded Song of the Siren heal her allies before Viper can finish them off.
Naga Siren
* Heroes with summons like Broodmother, Enigma, Nature's Prophet; or illusions, like Naga Siren, Terrorblade are effective at keeping the choke points and rune spawns safe from Proximity Mines.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, Medusa, Templar Assassin, Gyrocopter, Muerta.
Naga Siren
* Any long duration disables that can pierce through both, Pierce The Veil and Black King Bar are devastating against Muerta: Enigma's Black Hole, Dawnbreaker's Solar Guardian, Axe's Berserker's Call, Naga Siren's Aghanim's Scepter upgraded Ensnare and Reel In from Aghanim's Scepter, Jakiro's Aghanim's Scepter upgraded Macropyre, Bane's 
Fiend's Grip, 
Pudge's Dismember, Batrider's Flaming Lasso, Beastmaster's 
Primal Roar, Grimstroke's Soulbind, Medusa's Stone Gaze, Magnus's Reverse Polarity.
Primal Beast
* Fragile,slow heroes whom Pudge can outlive (Crystal Maiden,Muerta,
Sniper)
Naga Siren
* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, Witch Doctor.
Naga Siren
* Heroes with summons and illusions as Spirit Breaker has no strong AoE capabilities to deal with them: Chaos Knight, Phantom Lancer, Terrorblade, Naga Siren, Broodmother, Warlock, Visage, Nature's Prophet, Shadow Shaman, Lycan, Wraith King.
Primal Beast
* Durable heroes: Axe, Dawnbreaker, 
Bristleback, Mars, Omniknight, Tidehunter, Wraith King, Primal Beast, Underlord.
Primal Beast
* Heroes who have low or high armor but very high health will be difficult for drow to burst down quickly: Primal Beast, Axe, Centaur Warrunner.
Additional:
* Meat Hook can pull Drow Ranger to Pudge, disabling her 
Marksmanship.
* Following up with Dismember will prevent Drow Ranger from using 
Gust or 
Shadow Blade.
Naga Siren
* Heroes with summons and illusions such as Broodmother and Naga Siren, are ill-suited for Wraith King to fight, as he has no source of waveclear.
Primal Beast
* Heroes that have a channeled ability that can be interrupted by Meat Hook: Shadow Shaman, Witch Doctor, Enigma, Bane.
Primal Beast
* Heroes who build a Black King Bar (or have any sources of spell immunity) to channel abilities/items can still get interrupted by Dismember: Enigma, Juggernaut, Phantom Assassin, 
Pugna, Elder Titan.
Naga Siren
* Naga Siren with Mirror Image
* Heroes that can dodge Glimpse:
* Puck with 
Phase Shift
* Riki with 
Tricks of the Trade
* Phantom Lancer with Doppelganger
* Ember Spirit with Sleight of Fist and 
Activate Fire Remnant
* Chaos Knight with Phantasm
* Naga Siren with Mirror Image
* 
Tusk with 
Snowball
* Juggernaut with 
Omnislash
* 
Brewmaster with 
Primal Split
* Lifestealer with Infest
* 
Phoenix with 
Supernova
Primal Beast
* Heroes with many summons or illusions are much harder to catch with Meat Hook: Nature's Prophet, Phantom Lancer, Chen.
Naga Siren
* Naga Siren is a natural split-pusher. With a Radiance equipped, she will easily keep the lanes pushed out, therefore keeping backdoor protection enabled and preventing Nature's Prophet from dealing building damage.
* Ensnare can prevent Teleportation. Aghanim's Scepter upgraded Ensnare can also affect Nature's Prophet even if he is spell immune. And Reel In from Aghanim's Scepter can also be used to separate Nature's Prophet from his treant and bring him close to Naga Siren and her team to burst him down.
* Song of the Siren will stop Nature's Prophet from escaping even if he has hidden inside of Sprout. Aghanim's Shard upgraded Song of the Siren can also heal her allies and save them from Nature's Prophet.
Additional:
* Naga Siren is a natural split-pusher. With Rip Tide, she will easily out-push Nature's Prophet, farming his treants in the process.
* Ensnare prevents 
Teleportation. Even if he hides inside 
Sprout, Song of the Siren lasts long enough to prevent him from escaping.
Naga Siren
* Sand King and Phoenix have many tools to deal with multiple enemies at once, which will work well against a crowd of illusions.
Naga Siren
* Song of the Siren does not affect Supernova, which allows her and her team to focus the egg while the enemy team is affected by sleep.
* Phoenix cannot use 
Icarus Dive for escaping when rooted by Ensnare.
* However, Phoenix has many area-of-effect abilities that allow him to clear Naga Siren's illusions from Mirror Image.
Primal Beast
* Heroes with many summons or illusions are much harder to catch with Meat Hook: Nature's Prophet, Phantom Lancer, Chen.
Naga Siren
* Naga Siren can make landing Chen's combo very hard due to her being an illusion hero thanks to Mirror Image.
* Rip Tide can deal big damage to Chen and reduce Chen's armor, as well as easily kill all of Chen's creeps.
* Naga Siren often builds Radiance, which allows her to quickly clear Chen's creeps.
* Ensnare will prevent Chen from escaping.
* With Aghanim's Scepter, Naga Siren can get access to Reel In, which can separate Chen from his creeps and draw him closer to Naga Siren and her team to finish her off. To make things worse, Chen has no way to cancel Reel In on his own, and must rely on outside from {U:Centaur Conqueror} or {U:Mud Golem} under his control.
* Carry or Nuker Naga Siren can often finish off Support Chen before he can have a chance to activate 
Hand of God.
Additional:
* Naga Siren can make landing Chen's combo very hard due to her being an illusion hero.
* Rip Tide can deal big damage to Chen and reduce Chen's armor, as well as easily kill all of Chen's creeps.
* Naga Siren often builds Radiance, which allows her to quickly clear Chen's creeps.
* Ensnare will prevent Chen from escaping.
* With Aghanim's Scepter, Naga Siren can get access to Reel In, which can separate Chen from his creeps and draw him closer to Naga Siren and her team to finish her off. To make things worse, Chen has no way to cancel Reel In on his own, and must rely on outside from {U:Centaur Conqueror} or {U:Mud Golem} under his control.
* Carry or Nuker Naga Siren can often finish off Support Chen before he can have a chance to activate Hand of God.
Naga Siren
* Blade Fury offers good AoE damage to clear illusions and can hurt the real Naga Siren as well if she chooses to blend in the illusions. Diffusal Blade does nothing to Juggernaut either when he uses Blade Fury.
* Aghanim's Shard upgraded Blade Fury along with Lv 20 DPS talent will shred all illusions almost instantly, especially when combined with Mjollnir, a common item for Juggernaut.
Naga Siren
* Illusion-based heroes are effective against Omnislash and Juggernaut's single-targeted damage: Naga Siren, Chaos Knight, Terrorblade,Phantom Lancer.
Primal Beast
* Heroes who build a Black King Bar (or have any sources of spell immunity) to channel abilities/items can still get interrupted by Dismember: Enigma, Juggernaut, Phantom Assassin, Pugna, Elder Titan.
Naga Siren
* Dazzle can instantly destroy all of Naga Siren's illusions from Mirror Image with Aghanim's Shard upgraded 
Poison Touch used on her or any of her illusions.
Naga Siren
* Mirror Image's illusions can easily walk straight at Dazzle and attack him, due to Dazzle's lack of reliable AoE nukes or disables.
* Ensnare roots Dazzle or his allies, making it harder to stay in range of Dazzle's saving abilities.
* Song of the Siren can be used to initiate a fight with superior positioning, potentially zoning Dazzle's high-impact spells out of the fight.
Naga Siren
* Heroes that rely on illusions typically spawn very strong illusions inside Dark Seer Wall of Replica that he can use against them or their team: Phantom Lancer, Chaos Knight, Naga Siren, Terrorblade.
Primal Beast
* Abilities that deal low damage with high amounts of instances are irrelevant against Pudge during Flesh Heap's active: Gyrocopter's Rocket Barrage and Dark Seer's Ion Shell are just a couple examples.
Naga Siren
* Heroes who are illusion based, or even heroes who frequently build Manta Style can be cleared quickly by Pangolier's high damage, or lose their damage ouput because of Lucky Shot: Chaos Knight, Naga Siren
Naga Siren
* Heroes with powerful rooting abilities will disable most of Pangolier's skills, a bonus point if it pierces spell immunity since it will also be able to stop Pangolier during his Rolling Thunder: 
Treant Protector, Meepo, Crystal Maiden, Dark Willow, Underlord, Naga Siren
Naga Siren
* Zeus's abilities deal high amounts of burst magical damage, which ignores Naga Siren's high armor.
* 
Arc Lightning is a good way to destroy Naga Siren's illusions due to it's capabilities to bounce between enemies.
* 
Static Field from Aghanim's Shard can automatically hit everything in a big radius, taking a huge chunk of health out of Naga Siren's illusions, regardless of how much health they have.
Primal Beast
* Zeus likes to stay far back in fights, dealing his damage uninterrupted, but once he gets hooked into the fight, he usually dies very quickly.
* Pudge's high strength from Flesh Heap makes it very hard for Zeus to burst him down.
* Zeus' low health pool makes him very vulnerable to the damage from Meat Hook, Rot and Dismember.
Primal Beast
* Meat Hook can prove annoying for Pudge if Rubick 
Spell Steals it, allowing Rubick to easily hook and save his allies being Dismembered.
Naga Siren
* Song of the Siren is very difficult for Rubick to Spell Steal when he is affected by sleep.
* Ensnare and Rip Tide together with some attacks can take Rubick down quickly, due to his low health pool and armor.
* Naga Siren usually buys Diffusal Blade, which may prevent Rubick from using his abilities.
* Mirror Image allows Naga Siren to dodge the incoming stun from 
Telekinesis (when she is not a target), and it can also dispel 
Fade Bolt's damage reduction debuff.
Primal Beast
* Heroes with a high degree of mobility and invisibility are hard to catch with Meat Hook: Ember Spirit, Riki, Clinkz, Queen of Pain.
Naga Siren
* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.
Naga Siren
* Heroes with AoE nukes will clear her illusions in no time, especially if they are percentage-damage-based, like Underlord's Firestorm, Elder Titan's Earth Splitter, Enigma's Midnight Pulse, Zeus's Arc Lightning, Jakiro's 
Liquid Frost from Aghanim's Shard etc.
Primal Beast
* Heroes who build a Black King Bar (or have any sources of spell immunity) to channel abilities/items can still get interrupted by Dismember: Enigma, Juggernaut, Phantom Assassin, Pugna, Elder Titan.
Primal Beast
* Heroes with a high degree of mobility and invisibility are hard to catch with Meat Hook: Ember Spirit, Riki, Clinkz, Queen of Pain.
Primal Beast
* Heroes who recklessly jump on Pudge with their gap-closing abilities will be easy targets for Pudge's Meat Hook and Dismember Combo: Phantom Assassin, Faceless Void, Queen of Pain etc.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, Medusa, Templar Assassin, Gyrocopter, Muerta.
Naga Siren
* Ensnare prevents using any kind of movement abiilties, Making Naga Siren good against heroes who rely on gap-closing abilities to escape: Phantom Assassin, Magnus, Slark, Riki, Faceless Void, Storm Spirit.
Naga Siren
* Heroes whose attacks can affect multiple enemies at once will clear Naga Siren's illusions. Such heroes include Sven, Magnus, Dragon Knight, Luna, Medusa, Templar Assassin, Gyrocopter, Muerta.
Naga Siren
* Multiple attackers thanks to illusions: Phantom Lancer, Chaos Knight, Naga Siren (bonus for her Ensnare). Also despite the visual effects, Templar Assassin does not spill damage against illusions or buildings, so she is not a really good hero to clean up illusions.
* Heroes that can quickly deal damage to her, regardless of how weak they are, can easily break through her Refraction:
* Multiple attackers thanks to summoned units or clones: Meepo, Witch Doctor, Lycan, Enigma, Shadow Shaman
* Multiple attackers thanks to illusions: Phantom Lancer, Chaos Knight, Naga Siren (bonus for her Ensnare). Also despite the visual effects, Templar Assassin does not spill damage against illusions or buildings, so she is not a really good hero to clean up illusions.
* Weak damage but high tick rate or persist in a long time: Slark, Gyrocopter, Queen of Pain, Shadow Shaman (
Shackles), Jakiro, Pugna, 
Doom
Additional:
* Ensnare disables Templar Assassin's invisibility and Blink Dagger (a core item on Templar Assassin), and her illusions will break 
Refraction easily.
Naga Siren
* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, Witch Doctor.
Primal Beast
* Heroes that have a channeled ability that can be interrupted by Meat Hook: Shadow Shaman, Witch Doctor, Enigma, Bane.
Primal Beast
* 
Void's mini-stun and silence from 
Crippling Fear will stop Pudge from using Dismember or turning off his Rot.
* Night Stalker has naturally high health, strength gain and common itemization for survivability through magic resistance, making Night Stalker a poor target for Pudge.
Naga Siren
* Ensnare and Song of the Siren prevents Night Stalker from escaping and ganking during daytime or even nighttime.
* Rip Tide reduces Night Stalker's armor, making him easier to focus down.
* Mirror Image can be effective against Night Stalker, due to his single target abilities.
Additional:
* Mirror Image can be effective since Night Stalker cannot withstand fighting illusions. If he's unable to tell which Naga Siren is real, he will have a hard time landing his Void. However, if Night Stalker obtains an Aghanim's Scepter, the upgraded Void will hit and may even locate the real Naga Siren in fights.
Primal Beast
* Abaddon can activate Borrowed Time to dispel Dismember; breaking the disable and potentially allowing Abaddon to escape.
* Aphotic Shield can be cast on an ally to dispel the stun of Dismember, which can make kills difficult to secure, given that Dismember is Pudge's only reliable disable.
* Pudge lacks a mobility without a 
Blink Dagger, causing him to be easily chased with 
Curse of Avernus. The silence also prevents him from toggling off his Rot.
Naga Siren
* Song of the Siren completely wastes Abaddon Borrowed Time while keeping him in place.
* Naga Siren is able to simply dispel Abaddon's Curse of Avernus with Mirror Image before getting hit 4 times consecutively.
* Although Naga Siren's illusions can be easily destroyed by Aphotic Shield, Naga Siren can resolve that issue easily by purchasing 
Heart of Tarrasque to drastically increase her durability. Plus, the said item makes Naga Siren harder to be distinguished from her illusions.
Naga Siren
* Heroes with AoE nukes will clear her illusions in no time, especially if they are percentage-damage-based, like Underlord's Firestorm, Elder Titan's Earth Splitter, Enigma's Midnight Pulse, Zeus's Arc Lightning, Jakiro's Liquid Frost from Aghanim's Shard etc.
Primal Beast
* Heroes who build a Black King Bar (or have any sources of spell immunity) to channel abilities/items can still get interrupted by Dismember: Enigma, Juggernaut, Phantom Assassin, Pugna, Elder Titan.
Naga Siren
*
Arcane Orb allows Outworld Destroyer's attacks to deal pure damage that can bypass Naga Siren's armor, and which can clear her illusions in no time.
Astral Imprisonment can be used to harass Naga Siren by reducing her maximum mana and to prevent Naga Siren from escaping with Song of the Siren. Outworld Destroyer can also use 
Astral Imprisonment to protect himself from Naga Siren.
Sanity's Eclipse will most likely instantly kill Naga Siren along with her illusions. Even if Naga Siren survives 
Sanity's Eclipse, it's mana allergy debuff will discourage Naga Siren from using her abilities as the mana allergy will heal Outworld Destroyer if she uses them for it's duration.
*
*
Primal Beast
*
Sanity's Eclipse deals more damage the less max mana the heroes hit by it have, making Pudge an ideal target.
Astral Imprisonment.
* Outworld Destroyer can save allies or himself caught by Dismember or Meat Hook with