Tiny
* Heroes that are able to slow Tiny's attack speed, like 
Tusk and 
Phoenix, will greatly limit his Physical damage output.
Slardar
* 
Fire Spirits greatly reduces Slardar's already low starting attack speed (which Bash of the Deep relies on), making the laning phase very hard for him and discouraging Slardar from aggressively threatening lane kills.
* 
Supernova, ignoring Phoenix's lack of armor and Slardar's high damage single hits, is extremely hard for Slardar to take down on his own, especially after being hit by Fire Spirits.
* 
Icarus Dive is one of the longest distance escape spells in the game, and can help a good Phoenix escape from Slardar before he gets a 
Blink Dagger. However, the high cooldown means Phoenix is vulnerable to backstabs from any roamers after said spell is used.
* Slardar can interrupt an Icarus Dive from completing the flight with both of his stuns, however, likely leading to death if Supernova is on cooldown.
* A lot of the items a Phoenix builds throughout the game naturally counter Slardar. 
Shiva's Guard, 
Heaven's Halberd and 
Eul's Scepter of Divinity all stall Slardar's normal attacks in some way, while 
Spirit Vessel's percentage-based damage is good against his innate durability.
Tiny
* Heroes with high base damage (
Morphling, 
Tiny, 
Drow Ranger), heroes with mana burning abilities (
Anti-Mage), and 
Diffusal Blade users (
Juggernaut or 
Riki) will suffer from Reflection's illusions.
Slardar
* 
Terrorblade starts out with and gains a lot of armor from his agility growth. His illusions also make it difficult for Slardar to focus down the real Terrorblade.
Slardar
* Abaddon can cast 
Aphotic Shield on any of his allies to immediately dispel Corrosive Haze and/or the stun and the slow components of Slithereen Crush.
* All of Slardar's debuffs are also removed if Abaddon's 
Borrowed Time triggers.
Slardar
* 
Fortune's End applies a basic dispel which can be used to dispel Corrosive Haze, or even Slardar's own Guardian Sprint.
* 
False Promise is able to dispel Corrosive Haze and Slithereen Crush stun/slow from any allies Oracle chooses to cast it on.
* 
Fate's Edict can also be cast on Slardar to prevent him from proccing his Bash of the Deep.
Tiny
* 
Avalanche and 
Toss will never be enough damage to take out Sven in a clean way.
* Tiny is very slow with low armour growth and does not buy items to sustain Sven's damage output.
Tiny
* Tiny has low movement speed and attack speed, making him vulnerable to Viper's slows.
* 
Corrosive Skin provides magic resistance to lower Tiny's magic burst damage.
Tiny
* Dual Breath and Liquid Fire reduces Tiny's already abysmal Attack Speed.
* If Tiny Tosses a hero onto Jakiro, he can react with Ice Path, and potentially Macropyre.
* Tiny's Avalanche is easily countered with Ice Path.
* As Tiny has a very high Health, Liquid Frost is particularly effective against him.
Tiny
* 
Reaper's Scythe will turn Tiny's high health against him.
* 
Heartstopper Aura does substantial damage to Tiny as a result of his high max health.
* 
Ghost Shroud protects Necrophos from Tiny's physical damage with Tree Grab and Tree Volley.
Tiny
* 
Chaos Bolt and 
Reality Rift makes Tiny's low mobility non existent.
* 
Chaos Strike means Chaos Knight will most likely survive longer in a duel between the two because Tiny has much lower attack speed.
* Chaos Knight has a 3.2 strength growth, making him one of the most tanky heroes and a very difficult target for Tiny to burst.
Slardar
* Slardar has high priority on building moblity items such as Blink Dagger rather than tank items. Zeus can easily deal large amount of damage to him if not caught out of position first.
Slardar
* Phantom Lancer's 
Doppelganger has a low cooldown and applies a basic dispel on PL, making it hard to keep Corrosive Haze on him.
* Phantom Lancer usually purchases 
Manta Style which provides another basic dispel to remove Corrosive Haze with.
* Besides Slithereen Crush, Slardar does not have another way to deal with illusions and has a low mana pool, which allows Phantom Lancer with Diffusal Blade to quickly build up illusions while draining Slardar's mana.
* 
Phantom Rush outruns Guardian Sprint, forcing Slardar to Blink away or use Slithereen Crush defensively to avoid being killed.
Tiny
* Primal Roar and the slow from Boars make kiting Tiny very easy.
Tiny
* Heroes with Evasion or abilities that cause Tiny to miss like 
Phantom Assassin and 
Tinker are very effective because of Tiny's low attack speed. Additionally, 
Monkey King Bar is not a good item for Tiny because of its reliance on high attack speed to proc for magical damage.
Tiny
* Heroes without blink mechanisms or spell immunity will have a hard time positioning against 
Pit of Malice: 
Sven, Tiny, 
Wraith King, 
Dragon Knight, 
Meepo, 
Doom, 
Bounty Hunter, 
Dark Seer, 
Undying, 
Alchemist, 
Legion Commander.
Tiny
* Due to Tiny's non-existent agility gain, high physical damage heroes are more effective against him (
Clinkz, 
Templar Assassin, 
Ursa, Wraith King etc).
Slardar
* 
Bloodseeker's 
Rupture forces Slardar to stay still during fights, preventing Slardar from using Guardian sprint to move in and out of fights. This takes away the ability to initiate and re-initiate with Slithereen Crush's low cooldown. Due to the increased move speed from Guardian Sprint, Slardar can lose health at about 160% the rate of normal heroes while under Rupture. Bloodseeker's 
Thirst also gives him enough move speed so that he's one of the few heroes who can outrun or catch up to a Slardar during Guardian Sprint.
Slardar
* Enigma can be a perfect counter-initiator with his ultimate. A perfectly timed Black Hole will turn the tide of any initiation, especially from heroes like; 
Spirit Breaker, Legion Commander, 
Axe, 
Puck, and 
Slardar.
Tiny
* Heroes with Evasion or abilities that cause Tiny to miss like Phantom Assassin and Tinker are very effective because of Tiny's low attack speed. Additionally, Monkey King Bar is not a good item for Tiny because of its reliance on high attack speed to proc for magical damage.
Slardar
* 
Tidehunter's 
Kraken Shell dispels Corrosive Haze and Bash of the Deep's stun if enough damage is taken. 
Anchor Smash and Kraken Shell's damage block also reduces Slardar's damage.
Tiny
* Long ranged heroes like 
Sniper or Drow Ranger can kite Tiny effectively if he doesn't get the jump on them first.
Slardar
* 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.
Tiny
* Heroes that are able to slow Tiny's attack speed, like Tusk and Phoenix, will greatly limit his Physical damage output.
Tiny
* 
Feast will deal a enormous amount of damage because of Tiny's huge health pool.
* 
Rage protects Lifestealer from Tiny's magical burst damage.
Slardar
* Heroes with high physical damage can damage Lifestealer more than he can heal: 
Bristleback, Clinkz, Luna,
Shadow Fiend, Slardar, Terrorblade
Tiny
* Invoker is a big problem for Tiny the whole game because of its multiple disables. For example, the 
Cold Snap ability can catch an attack from Tiny's hand by surprise, because it becomes slower with the pumping of 
Grow. has a giant deceleration, creating a condition for the kite, which Tiny is very afraid of. In addition, Invoker has a 
Deafening Blast that disables Tiny's main weapon - strong blows from the hand
Additional:
* Invoker is a big problem for Tiny the whole game because of its multiple disables. For example, such as 
Tornado + 
E.M.P. create unrealistic conditions for Tiny with mana, which is very necessary for Tiny at least for some attacks in a fight. The Cold Snap ability can catch an attack from Tiny's hand by surprise, because it becomes slower with the pumping of Grow. has a giant deceleration, creating a condition for the kite, which Tiny is very afraid of. In addition, Invoker has a Deafening Blast that disables Tiny's main weapon - strong blows from the hand
Slardar
* Bounty Hunter and Slardar both have ultimates (
Corrosive Haze and 
Track) that reveal Invoker through Ghost Walk.
Tiny
* Toss and Avalanche deals heavy damage to Slark in the early game, making Tiny a very dangerous target to gank.
* Tiny has 0 agility, which means Slark's 
Essence Shift permanent agility steal does not do much against him.
Slardar
* Slardar's level 25 talent makes Corrosive Haze undispellable, thus providing his allies vision of Slark.
Tiny
* Side lanes with disables will greatly reduce the likeliness Void Spirit will be willing to rotate: Sven, Tiny, Wraith King, 
Ogre Magi.
Slardar
* The brutal physical damage of 
Slithereen Crush and 
Bash of the Deep can quickly remove Void Spirit's shield and stun him for a while.
* Corrosive Haze provides vision of Void Spirit while he is running away and 
Guardian Sprint allows Slardar to quickly close the gap
Slardar
* Corrosive Haze and Bash of the Deep will make short work of Huskar's low armor, even if Slardar is alone.
Slardar
* Slardar deals entirely physical damage. He does not have to worry about Counterspell.
* Slithereen Crush and Bash of the Deep prevent Anti-Mage from using Blink, the latter even if Anti-Mage activates 
Black King Bar.
* Corrosive Haze allows allies to take down Anti-Mage before he has a chance to Blink, and maintains vision over him even if he does Blink away.
Additional:
* Slithereen Crush and Bash of the Deep deals physical damage, bypassing the magic resistance bonus from 
Counterspell
* Corrosize Haze significantly increases the damage dealt against Anti-Mage, and makes it harder for him to flee with 
Blink, although Anti-mage can block its casting with with Counterspell
Slardar
* Shadow Fiend, a normal 
Shadow Blade builder often relies on its invisibility to escape fights. Corrosive Haze reveals Shadow Fiend and also weakens his already low armor.
Slardar
* 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.
Additional:
* While Slardar has Guardian Sprint activated, 
Rot cannot slow him and 
Meat Hook is easier to avoid.
* Slithereen Crush allows Slardar to interrupt 
Dismember at close range (when Slardar is not a target).
* Corrosive Haze reveals Pudge's location, making it very difficult for him to land hooks from the fog.
Slardar
* Corrosive Haze works much like Track, giving the enemy team vision over Riki. While it doesn't give a movement speed or gold bonus, it instead can melt Riki's armor and Slardar can use Guardian Sprint to catch up to him.
* Slardar's 
Aghanim's Shard, causes Slithereen Crush to apply Corrosive Haze even if Slardar does not have vision over him.
Additional:
* Corrosive Haze makes Riki completely vulnerable to Slardar and his allies, as Riki has no easy way of dispelling it.
* Slardar's physical damage with Slithereen Crush and Bash of the Deep amplified by Corrosive Haze can easily kill Riki.
Slardar
* Corrosive Haze hinders Nyx Assassin's ganking attempts with 
Vendetta, as well as reducing his armor and make him very vulnerable due to his low health pool.
* Guardian Sprint allows Slardar to catch up with Nyx Asssassin and finish him off if he has vision over him.
Slardar
* Weaver relies on 
Shukuchi to escape and kite enemy heroes. Slardar's Corrosive Haze lowers armor and reveals Weaver, who is already a very frail target.
* Weaver usually builds 
Linken's Sphere, Corrosive Haze can be used to pop the spell block, additionally the level 25 undispellable talent will prevent Weaver from removing Corrosive Haze with 
Time Lapse, allowing allied heroes to use their abilities on Weaver.
Additional:
* Corrosive Haze lowers armor and reveals Weaver during Shukuchi, who is already a frail target. In addition, Weaver usually builds Linken's Sphere, and Corrosive Haze can be used to "pop" the spell block. His level 25 talent can also make Corrosive Haze undispellable by Time Lapse, which puts Weaver in an even worse situation.
* Guardian Sprint can dodge Weaver's bugs with the movement speed bonus.
Slardar
* While Slardar has Guardian's Sprint activated, 
Powershot cannot slow him and is easier to avoid.
* Slithereen Crush and Bash of the Deep help Slardar put Windranger in place, even when she uses 
Windrun to escape.
* Corrosive Haze from Slardar is very effective against Windranger's already low armor. This becomes even worse if she has 
Aghanim's Scepter-upgraded Windrun, because it also reveals her position and allowing his allies to use their abilities on Windranger.
* Note that the invisibility provided by Aghanim's Scepter-upgraded Windrun is not broken upon attacking, casting abilities or using items, so it's vital to cast Corrosive Haze beforehand.
Slardar
* Corrosive Haze provides True Sight on its target, exposing Bounty Hunter's position regardless of Shadow Walk.
* Guardian Sprint gives a very high movement speed bonus, allowing him to chase Bounty Hunter even if Slardar is tracked.
Additional:
* Bounty Hunter's 
Shadow Walk is rendered useless with Corrosive Haze and makes Bounty Hunter an easy target for Slardar and his team.
Tiny
* Tiny can quickly clear Spiderlings with his active abilities and cleave.
Slardar
* With armor items like 
Solar Crest or 
Assault Cuirass combined with Bash of the Deep, Slardar can easily tank the 
Duel, If not dueled himself, he can drop Legion Commander's armor during duel and/or buff his teammate and save them, leaving her only the choice of dueling supports which can also be saved with fast Blink into Slithereen Crush.
Tiny
* Tiny can be a serious problem for the distance between Lone Druid and his 
Summon Spirit Bear with his Toss ability, since he will throw one away from the other, giving his team the opportunity to deal with either the Summon Spirit Bear or Lone Druid himself
* Lone Druid will not always be in his 
True Form, since she has her own recharge, which is why Tiny can find him with a Shadow Blade or Blink Dagger and kill him in a second with a combination of Avalanche and Toss, due to the fact that Lone Druid has a very small health reserve without True Form
Additional:
* Tiny can be a serious problem for the distance between Lone Druid and his Summon Spirit Bear with his Toss ability, since he will throw one away from the other, giving his team the opportunity to deal with either the Summon Spirit Bear or Lone Druid himself
* Lone Druid will not always be in his True Form, since she has her own recharge, which is why Tiny can find him with a Shadow Blade or Blink Dagger and kill him in a second with a combination of Avalanche and Toss, due to the fact that Lone Druid has a very small health reserve without True Form
Slardar
* Corrosive Haze will reveal Treant Protector even when he is under the effects of Nature's Guise.
Slardar
* Slardar can attack through Plague Wards and gain Bash of the Deep charges, and Templar Assassin can spill 
Psi Blades through Plague Wards too.
Slardar
* Heroes with spells that negate invisibility such as Bounty Hunter, 
Zeus and Slardar prevent her from saving her allies with Moonlight Shadow.
Tiny
* Due to Tiny's non-existent agility gain, high physical damage heroes are more effective against him (Clinkz, Templar Assassin, Ursa, Wraith King etc).
Tiny
* Heroes that have disposable area-targeted spells can force her to undo her Meld: 
Leshrac, Puck, Tiny, 
Jakiro,. An experienced Templar Assassin could try to use Refraction before Meld so she can tank through those damage without getting her Blink disabled.
Slardar
* Heroes who can provide True Sight are always credible threats: Slardar, Bounty Hunter, especially Zeus since his 
Lightning Bolt provides True Sight without the need to detect her beforehand to apply the debuff. So even a late-coming Zeus can easily scout a large area to reveal her, and she cannot purge herself from his sight with the dispel talent.
Slardar
* Slardar can chase Dragon Knight down with Guardian Sprint and stun him with both Slithereen Crush and his passive Bash of the Deep. He can also use Corrosive Haze to whittle Dragon Knight's armor.
Slardar
* Heroes who can provide True Sight or semi-reveal enemy heroes as Nature's Prophet is prone to buying Shadow Blade: Bounty Hunter, Slardar, 
Spectre, Zeus, Spirit Breaker.
Slardar
* Slardar's Slithereen Crush allows him to stun Spectre and illusions, and Corrosive Haze prevents her from juking with 
Spectral Dagger.
Slardar
* 
Crystal Maiden's already low armor and easily interruptible ultimate, 
Freezing Field can make Slardar her worst nightmare. Crystal Maiden also often builds 
Glimmer Cape which is revealed by Corrosive Haze.
Tiny
* Squishy heroes, usually supports, like 
Lion, 
Ancient Apparition, 
Keeper of the Light etc can die quickly to Tiny's magic burst.
Tiny
* Squishy heroes, usually supports, like Lion, Ancient Apparition, Keeper of the Light etc can die quickly to Tiny's magic burst.
Tiny
* Familiars will easily be able to kite heroes with a short range or with low attack speed. For example, Tiny and Undying have a very hard time killing Familiars.
Tiny
* Tiny can deal with 
Visage's 
Gravekeeper's Cloak quickly, as Avalanche deals damage in enough instances to completely remove all 4 layers of the passive. With Visage's lower than average Armor, a well positioned stun can allow Tiny to kill Visage easily.
Additional:
* Tiny's Avalanche removes a significant number of layers from Gravekeeper's Cloak. When combined with Toss burns through all of Gravekeeper's Cloak while doing triple times Toss damage to Visage in midair.
* Tiny's already high damage coupled with 
Tree Grab's attack modifier will make short work of Visage's Familiars.
Slardar
* Heroes with armor reducing abilities greatly hinder Visage's defense like Slardar and 
Dazzle.
Slardar
* 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.
Tiny
* 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.
Tiny
* Long ranged heroes like Sniper or Drow Ranger can kite Tiny effectively if he doesn't get the jump on them first.
Slardar
* Slardar can use Guardian Sprint with Blink Dagger or Shadow Blade to get close, and Slithereen Crush will stun Sniper and slow him, making him vulnerable to Slardar's teammates.
* Corrosive Haze lowers Sniper's armor and makes Sniper's Shadow Blade useless, easily killing him with a few attacks.
Tiny
* He can quickly take out heroes with low armor (Tiny) with his great physical damage.
Slardar
* Corrosive Haze followed by Slithereen Crush takes advantage of Alchemist's main weakness, being physical damage before he has the change to improve his surviability with items.
* Bash of the Deep will deal lots of damage during the laning phase.
Tiny
* Due to Tiny's non-existent agility gain, high physical damage heroes are more effective against him (Clinkz, Templar Assassin, Ursa, Wraith King etc).
Slardar
* Slardar can reveal Clinkz with Corrosive Haze and make him easy to kill, and his Bash of the Deep also hits hard against Clinkz's naturally low health pool.
* Slardar's Guardian Sprint can catch up with Clinkz's Skeleton Walk.
* The stun and slow from Slardar's Slithereen Crush can hold Clinkz in place.
Additional:
* Clinkz survivability depends entirely on 
Skeleton Walk. Corrosive Haze not only makes its invisibility useless, but also makes Clinkz even more vulnerable to physical damage.
Tiny
* Due to Tiny's non-existent agility gain, high physical damage heroes are more effective against him (Clinkz, Templar Assassin, Ursa, Wraith King etc).
Slardar
* Slardar is one of the few meele heroes who can lane against Ursa in the early game, out harassing him with Bash of the Deep, and running away from a bad engagement with Guardian Sprint
* Corrosize Haze can force Ursa to cast 
Enrage defensively instead of offensively
* With Corrosize Haze, Slardar's team can quickly dispatch of Roshan, denying one of Ursa's greatest advantages
Slardar
* Slardar does not do well against multiple targets, as his only way to damage multiple targets is Slithereen Crush.
* Meepo's 
Earthbind will root Slardar, making him unable to chase/escape for the time being. Also, 
Poof's low cooldown and high damage can burst Slardar down rather quickly.
Tiny
* Tiny's Avalanche affects all Meepos and Toss can send a singular Meepo into death.
Additional:
* Avalanche and Toss prevents Meepo's from using Poof to escape.
* Tiny doesn't need to target the weakest clone while he is affected by Tree Grab.
Slardar
* Heroes who can stun multiple units at once: 
Dark Willow, Spirit Breaker, Slardar, 
Invoker, and Tidehunter.
Tiny
* Tiny's nonexistent armor in the early game makes him very vulnerable to 
Quill Spray's large amounts of physical damage.
* 
Bristleback decreases Tiny's high burst damage against Bristleback.
* 
Viscous Nasal Goo can slow Tiny to a crawl and allows Bristleback to easily kite him with his high movement speed and Quill Spray's long range, as Tiny has no ability to escape.
Slardar
* Guardian Sprint allows Slardar to outrun Bristleback, even when slowed by Viscous Nasal Goo.
* Corrosive Haze's armor reduction makes Bristleback much less tanky.
Tiny
* 
Mana Drain has an fair long range and low cooldown. It can easily deplete most heroes of their entire mana pools, especially those with smaller mana pools such as Tiny or Spirit Breaker.
Additional:
* Lion can continuously Mana Drain Tiny in the early game, depleting his small mana pool for his abilities.
Tiny
* Squishy heroes, usually supports, like Lion, Ancient Apparition, Keeper of the Light etc can die quickly to Tiny's magic burst.
Slardar
* 
Medusa cares less than other heroes about armor reduction, since 
Mana Shield blocks 70% of all damage without taking armor/magic resistance into consideration. This makes 60% of your Corrosive Haze ineffective until Medusa's mana is drained.
Slardar
* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: Tidehunter, Bristleback, Slardar.
Tiny
*
Blade Fury protects Juggernaut from all of Tiny's magic burst damage.
Slardar
* 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.