Pharah:  One of Pharah's worst nightmares is being hooked by a Roadhog, and it isn't too difficult for a Roadhog to hook a Pharah as long as she comes within range of him, and it usually results in a kill for Roadhog.  Roadhog also has decent medium range with his alternate scrap gun fire, making Pharah a somewhat easy target for him.  Pharah's rocket spam from further away can be a nuisance, but Roadhog's massive hitpoints and healing only makes it harder for a Pharah to take him out.  Keep in mind she can use a Concussive Blast to knock you back, making it harder to Chain Hook her.

Roadhog's Chain Hook is one of the best counters in the game for Pharah's ultimate Barrage, which will totally cancel the effect and yank her close to you to take her out.  Pharah's best bet at countering a Chain Hook is by jump jetting away while at the same time using a Concussive Blast to propel herself away as well.

Tracer:  Whilst it is difficult for Roadhog to kill Tracer due to her superior mobility, this isn't a fight Tracer can win.  It's incredibly hard to Chain Hook a Tracer due to her fast unpredicted movements, and even if you do manage to hook her in, she can just use a Recall to get out of it.  Blinks can also work to escape after getting hooked if Recall is not available to her.  Tracer's Pulse Rifle spam can be a nuisance and charge her ultimate up faster but Roadhog can easily tank it and heal it back up with his Take a Breather ability.

Roadhog is one of the few heroes in the game that can survive Tracer's Pulse Bomb explosion.  Pulse Bombs do up to 400 damage and Roadhog has 600 total HP.  Whole Hog is not too useful against Tracer as she can simply Blink away from it to avoid it.  Pulse Bombs do not have any stun effects, so it will NOT cancel out Take a Breather (self-heal) or Whole Hog.

Overall, Roadhog is typically not a prime Target for Tracer, or vice versa.  Tracer is better off dealing with other heroes and keeping her distance from Roadhog.

D.va:  Since D.va's mech has a large hitbox, Roadhog's Scrap Gun happens to be very powerful against her.  It's relatively easy to Chain Hook D.va since she moves very slow while firing.  After getting chained in, D.va can attempt to boost away from Roadhog, or backup while using Defense Matrix to avoid further damage.  If she does use Defense Matrix, just use melee attacks as that can go through it.

Keep in mind you can still Chain Hook D.va while she is using her Boosters or her Defense Matrix ability.

Overall it will be tough for D.va to take out Roadhog, even from a distance since Roadhog can easily heal up his damage with his Take A Breather ability.  D.va's Boosters will knock back Roadhog, but it will NOT cancel the heal effect of his Take a Breather ability.

When Roadhog uses his ultimate Whole Hog, D.va can easily block it with her Defense Matrix ability, protecting her whole team from it.

Since Roadhog has poor mobility and slower movement, he will have a harder time taking cover from D.va's Self-Destruct ultimate.  D.va also has the option to use her Self-Destruct on Roadhog while he's using Whole Hog since he will be forced to keep firing until it is over, this can quite easily take him out.

Mercy:  Mercy's flying ability makes her very susceptible to Roadhog's Chain Hook.  She is usually hiding away around corners from her enemies, but occasionally you will see her flying around to other heroes and sometimes even floating in the air with her Angelic Descent ability, especially when she is healing heroes such as Pharah.  Always keep an eye out on her and Chain Hook her every chance you get.  Once chained in, she cannot do much to escape it except to try to use her flying ability to go back to a nearby ally, but by then she will most likely perish to your Scrap Gun.

Whole Hog can be used on Mercy to bat her away from healing her allies, but she can just use her Guardian Angel ability to catch back up to her allies.

If you see Mercy using Resurrect, quickly try to Chain Hook one of the resurrecting enemies to yank them in right when they get resurrected.

Zenyatta:  Zenyatta has many counters for Roadhog.  Since Zenyatta is a support hero, he typically stays back behind his team, usually far enough that Chain Hook won't reach to him.  If Roadhog actually does manage to Chain Hook Zenyatta in, Zenyatta will most likely die unless you miss a headshot and he uses his ultimate Transcendence to save him.  Also, if Roadhog Chain Hooks an enemy in, Zenyatta can throw an Orb of Harmony on that player to potentially keep him alive.

Zenyatta's main attack weapon (Orb of Destruction) happens to be very deadly against Roadhog due to his large hitbox and slow movement.  Zenyatta can also dish out a lot of damage to Roadhog with his charged volley orb shots.  And this becomes especially deadly when Zenyatta throws an Orb of Discord on Roadhog beforehand.

Zenyatta's Orb of Discord does 30%+ more damage to the enemy that has the orb on them.  Roadhog is a prime target for the Orb of Discord, because his only shield is his own hitpoints.  Orb of discord makes Roadhog very susceptible to damage and can make taking him out much easier.  As Roadhog, your slow movement will make it a lot harder to get behind a wall to remove the Discord Orb.  You will need to keep up with your canister healing more frequently when Orb of Discord is on you.

Roadhog can actually Chain Hook Zenyatta's ultimate Transcendence, although it will not cancel the ability, but it will still pull the transcending Zenyatta into Roadhog.  This can act as good crowd control for your offensive attackers, allowing them to dish out damage to the enemies that are away from Transcendence.

Zenyatta's Transcendence is a decent counter to Whole Hog, but Whole Hog will still knock back Transcendence though.

Ana:  Ana works great against her enemies that have healing capabilities thanks to her Biotic Grenade.  Out of all the tanks, Roadhog is the easiest one for Ana to deal with.  Since Roadhog has a self-heal, Ana can use her Biotic Grenades on him to prevent him from using it for a short period of time, this can easily mean the death for Roadhog in many situations.

Roadhog's large hitbox makes hitting him fairly easy for Ana's Biotic Rifle and especially her Sleep Darts.  Putting Roadhog to sleep is very deadly as it will keep your deadly Chain Hook out of the game for a short while along with your insane close up Scrap Gun DPS.

Since Ana is a Sniper, she is generally far away enough from Roadhog to avoid your Chain Hook, but if you do manage to Chain Hook Ana in, you better land all your shots quickly or she can throw a Sleep Dart at you to escape easily.  Ana can also save one of her allies being chained in by Roadhog by giving them a Nano Boost (Ana's ultimate).  A Nano Boosted enemy in general can make easy work of Roadhog and will be able to deal with all your abilities more effectively.  Only consider chain hooking a Nano Boosted enemy in if that enemy is already very low on health.

Whole Hog can easily be countered by Ana's Sleep Dart.  Whole Hog is also one of the few ultimates that will actually end for good if Ana puts you to sleep while using your ultimate.

Hanzo:  Since Hanzo is not a close up combatant, he does well against Roadhog since he is usually out of reach from Roadhog's Chain Hook.  Hanzo's Sonic Arrow further helps him stay out of Roadhog's reach and helps him to aim and ricochet Scatter Arrows at the same time at him.  If Roadhog does actually manage to Chain Hook Hanzo in, Hanzo will most likely die as there is not much he can do about it except fire a Scatter Arrow, which won't do much to Roadhog.

Since Roadhog is a slow moving hero with poor mobility, it's generally very easy for Hanzo to aim bow shots at him, and Roadhog will have a harder time dodging Hanzo's ultimate Dragonstrike due to his poor mobility as well.

One negative aspect of Whole Hog is Hanzo's Dragonstrike is a good counter to it, as Roadhog will be unable to move very fast for 6 seconds while it's in use, thus not giving him enough time to avoid the Dragonstrike.

Torbjorn:  Roadhog's poor mobility makes countering Torbjorn's turrets incredibly difficult for him.  Turrets are also hard to hit due to Roadhog's poor long range damage with his Scrap Gun.  Torbjorn is usually out of reach of Roadhog's Chain Hook, but if Roadhog actually manages to Chain Hook Torbjorn he can simply use Molten Core to counter it if its available, otherwise Torbjorn will most likely die.

Roadhog's ultimate Whole Hog is less effective on Torbjorn since he is usually able to take cover by his turret and away from the shrapnel rounds.

Lucio:  Lucio can be difficult to Chain Hook due to his fast ground mobility, especially when he has his speed aura on.  His Speed Aura can also make his entire team more difficult to Chain Hook.  However, Lucio players normally use heal aura more often instead, this will make Chain Hooking enemies a normal thing most of the time.

If you do happen to Chain Hook Lucio in, he can use his Soundwave ability to knock you away from him, allowing him to avoid further damage.  He can then use his speed aura with an Amp It Up to escape, or he can also use his ultimate Sound Barrier to save himself (or one of his allies) as well.  As you can see, Chain Hooking Lucio is virtually useless most of the time as long as you do not land that quick headshot on him after chain hooking him in.

Dodging Lucio's Sonic projectiles can be a bit difficult due to Roadhog's large hitbox and slower movement.  This can help rev up Lucio's ultimate faster.

Whole Hog can be countered by Lucio's Sound Barrier, if it's available to him.

Junkrat:  Junkrat is usually in the clear of Road Hog's abilities, especially his Chain Hook.  Since Junkrat is mostly in the distance lobbing grenades, usually behind a wall or object, he is safe from Roadhog's Chain Hook and Whole Hog ultimate most of the time.  Roadhog's poor mobility and Junkrat's superior mobility (with his mine jumps) makes it harder for Roadhog and his Chain Hook to get close to Junkrat.

Roadhog's slow movement speed is an advantage at helping to avoid Junkrat's traps and mines before running over them.  If you do happen to Chain Hook a Junkrat in and you miss that lethal headshot, he will most likely throw out a Trap/Mine combo at you which will do about 200 damage, but that can be easily healed up with your canisters.

Junkrat's Rip-Tire has the capability to kill Roadhog at full health, and since Roadhog is such a slow moving hero, Rip-Tires can easily take him out.  Keep in mind that Roadhog can actually Chain Hook a Rip-Tire into him.  However, while the tire is being chained in, Junkrat can still detonate it at any time he wants to.

Soldier 76:  Since Roadhog is such a big target, Soldier 76's Pulse Rifle works very well at nearly all ranges against him.  Soldier 76 is best to keep his distance from Roadhog, but if he manages to get closer, Chain Hook him in and he will be an easy kill for you then.

Soldier 76 can use his Sprint ability to move further away from Roadhog, further avoiding everything Roadhog can do to him.  TIP:  Using Whole Hog will make Soldier 76 get knocked back, even while he's sprinting.

Roadhog is a prime target for Soldier 76's  Helix Rockets, since Roadhog is big and slow moving, which makes aiming Helix Rockets at him very easy for Soldier 76.

Soldier 76's ultimate Tactical Visor is less efficient to use on tanks, so Roadhog should usually be in the clear of it.  Tactical Visor does NOT get canceled if Roadhog Chain Hooks a Soldier 76 using it, but Soldier 76 still has a high chance of death with the Scrap Gun shot and melee combo afterwards.

Mei:  Mei is tough to deal with mostly because of her Ice Wall.  Chain Hooking Mei may be somewhat easy to do but if you miss that lethal headshot she can easily counter it with an Ice Wall right in Roadhog's face, allowing her to then escape.  Her Ice Wall also protects her team from Roadhog's Scrap Gun shots, and even Whole Hog as well, literally making Whole Hog useless, but only for a short period of time as Whole Hog can destroy an entire Ice Wall before its duration is up.

If Mei gets close to you and starts to channel her freeze gun on you, quickly Chain Hook her in before she freezes you in place.  Whole Hog can also knock her back and restart the freeze status.

Roadhog's large hitbox and slow movement, makes him an easy target for Mei's long range Icicle shots, and since Roadhog has really poor mobility, Mei's ultimate Blizzard happens to work really well on him.  Blizzard can also freeze Whole Hog, which is another method of Mei disabling Roadhog's ultimate (besides Ice Wall).

Roadhog's Take a Breather can be canceled by Mei freezing him either with a Blizzard or her freeze blaster.

Roadhog:  Battling another Roadhog comes down to who Chain Hooks who first.  Chain Hooking another Roadhog toward your team can easily take him out as Roadhog has no escape mechanisms.  If you do happen to get Chain Hooked by another Roadhog you can use Whole Hog if it's available and you have enough HP to live through it.  Otherwise just do your Scrap Gun shot / melee combo, then heal, and hope for the best.  Also remember that you can cancel another Roadhog's Take a Breather by Chain Hooking him.

When Roadhogs keep a distance from each other, then the alternate Scrap Gun fire becomes the name of the game then, along with canister healing.

And remember when another Roadhog is using Whole Hog, a Chain Hook on him will cancel the entire ultimate and then give you and your team an easy kill.  With this in mind, it's important to only use Whole Hog immediately right after the enemy Roadhog uses his Chain Hook, so it won't be available to him for use during your Whole Hog.

Winston:  Winston's Barrier shield is what makes dealing with him so difficult.  His Barrier shield protects his team from Roadhog's Scrap Gun shots and also blocks Chain Hooks as well.  When Winston's barrier is up would be a good time to use a canister heal.  When the Barrier goes down is when Roadhog can make his Chain Hook moves more effectively.

Chain Hooking Winston in can be effective, but he can counter that by either leaping away or turning his Primal Rage ultimate on.  Primal Rage can be tough to deal with if you don't have enough fire power from your allies to help you.  However, Whole Hog can be used to knock Primal Rage back away from you and your team.  Also, don't bother Chain Hooking a Primal Rage Winston in, as you are just asking for trouble.

Keep in mind that a Jump Pack landing from Winston will NOT cancel out Roadhog's Take a Breather ability.

If Roadhog uses Whole Hog, Winston's Barriers are an excellent counter to it.

Reinhardt:  Even though Reinhardt can use his shield to block Roadhog's Chain Hook, Roadhog can still manage to Chain Hook Reinhardt from any slight moment when he does lower his shield.  Chain hooking a Reinhardt in can be tough to deal with as he is very deadly in close range, as he can use any one of his abilities to protect himself after getting chained in.  Only Chain Hook Reinhardt in if you know for sure that your allies are there to provide the necessary fire power to help take Reinhardt down.

Keep in mind you can still Chain Hook a Reinhardt while he is Charging at something, this can potentially save you or one of your allies from getting pinned.  Also using Whole Hog against a Reinhardt Charge can disable it from continuing.

Roadhog's Scrap gun happens to be very deadly against Reinhardt's Shield, as it's the most powerful basic attack weapon (besides a Bastion Sentry) that can take Reinhardt's shield down the fastest.  And this is especially the case when Whole Hog is used against Reinhardt's shield.  However, Reinhardt can counter Whole Hog with his ultimate Earthshatter, which will totally cancel it.

Take a Breather can be canceled with Reinhardt's Charge or Earthshatter.

Reinhardt's Fire Strike happens to be very deadly against Roadhog since he is a big target that also moves slow, thus making it easier to land Fire Strikes on him, this in turn will rev up Reinhardt's ultimate up faster.  Keep in mind that Reinhardt has to lower his shield when he launches a Fire Strike, this can give you a chance to Chain Hook him in at these times.

Bastion:  Getting close to a Bastion Sentry to Chain Hook him can be difficult due to his insane DPS.  However, if you do manage to get close and Chain Hook him in, there is not much he can do to counter it and will most likely die to you then.

If you see Bastion use his Tank ultimate, quickly try to Chain Hook him into you and quickly finish him off.

Whole Hog is usually not very useful against a Bastion Sentry as his armor can protect him from the shrapnel shots while he dishes out a good amount of DPS to you in return.  Plus Whole Hog's main use is to knock back enemies, but this has no effect against stationary Bastion Sentries.

Zarya:  Zarya's Particle Barrier will block your Chain Hook.  The key to dealing with a Zarya is to only bother Chain Hooking her immediately once her Particle Barrier goes down and goes on a cooldown, as that is your only chance to pull it off successfully, otherwise she can escape your Chain Hook by simply using her Particle Barrier.  Another way for her to help escape out of a Chain Hook is she can use her ultimate Graviton Surge, which will put you and your allies in a magnet like clump and you won't be able to move, but you will still be able to shoot.  She can also use a Projected Barrier on one of her allies to save them from a Chain Hook as well.

Zarya can do a lot of damage to Roadhog from afar with her explosive particle charges, and since she has the smallest hitbox out of any tank, it will be harder for Roadhog to do damage with his Scrap Gun at a long range.

While using Whole Hog, be very careful if Zarya uses her Particle Barrier, avoid aiming in her direction or she will absorb the damage making her stronger.

Genji:  Genji's long distance shuriken damage can be quite lethal to Roadhog and you will need to keep up with your canister healing to deal with that.

From medium to long distances, Genji's Deflect is very weak on your Scrap Gun.  However if you Chain Hook Genji, be sure to land that headshot quickly, or he can then use a Deflect right up close to you and reflect all the damage right back at you which will hurt you quite a bit.  Be extra careful when Genji uses Deflect after Chain Hooking him in, instead just use melee strikes as he cannot deflect that (he can only block it with Deflect).  Genji can also use a Deflect to block your Chain Hook attempts.

Genji's ultimate Dragonblade happens to be somewhat effective against Roadhog.  It will take 5 swipes from his blades to take out a Roadhog from full HP.  Whole Hog can be used to counter Genji's Dragonblade by knocking him back away from you and other allies.  Chain Hook will NOT cancel Dragonblade though.

Reaper:  Reaper's Wraith Form can be a strong counter to Roadhog's Chain Hook.  If you miss that initial headshot after Chain Hooking Reaper in, he can use Wraith Form to escape unharmed.  If Wraith Form is still on a cooldown, then there is a good chance you will be able to take him out.

Reaper's ultimate Deathblossom can be countered by using a Chain Hook on him to cancel the ultimate.  If Chain Hook is not available you can also use Whole Hog to knock him away from your allies.

McCree:  Both heroes deal decent damage in close to medium range, although McCree does a bit more DPS, Roadhog has much more health to compensate.  Chain Hooking McCree can be somewhat difficult because a good McCree player can use a Combat Roll to dodge it.

You want to be cautious getting too close to McCree as he can Flashbang and then fan fire you, which is a very deadly combination.  Your Chain Hook combo is still the only way to counter this as Roadhog.

McCree's Flashbang will cancel all of Roadhog's abilities, including:  Take a Breather and Whole Hog.

Dealing with McCree's ultimate (Deadeye) as Roadhog is easy.  McCree will stand in place while lining up shots, during this time you can Chain Hook him and it will totally cancel the ultimate.  Deadeye works on hero hitpoints, the more hitpoints a hero has the longer it will take for McCree to line up a shot for that hero.  Since Roadhog has the highest HP in the game, it will take McCree the longest to line up a shot against him (as long as Roadhog's HP is nearly full).

Widowmaker:  The problem with Widowmaker is she is usually far off in the distance away from Roadhog and his Chain Hook.  This can make dealing with her a problem for Roadhog.  Generally Roadhog will rely on his offensive heroes to really deal with taking out Widowmaker.  Since Roadhog has very high HP with a self-heal, it will take a lot of snipe shots from Widowmaker to take him out.  Widowmaker is better off sniping heroes with less HP first before Roadhog.  This means that both heroes generally leave each other alone for the most part.

If Roadhog actually manages to Chain Hook Widowmaker toward him, she can quickly grapple hook away from him to avoid further damage, but Roadhog will still have plenty of time to deal good damage to her before she does grapple away.

Roadhog's Scrap Gun doesn't have the best range, even with his ultimate Whole Hog, so Widowmaker usually doesn't take too much damage from him overall.

Symmetra:  Symmetra is a support hero that usually stays back from the front lines putting up Sentry Turrets or lobbing Photon Orbs.  Because of this, Roadhog will rarely have the chance to Chain Hook her.  But if you do so happen to Chain Hook her, she will be a sitting duck as there is nothing she can do to escape or repel damage back to you.

Watch out for Symmetra's Photon Orbs.  Her orbs fly slow, but are very deadly.  It is also Symmetra's main way of charging up her ultimate Teleporter, so do your best to strafe around them.

Since Roadhog's short range Scrap Gun has a nice spread, it makes shooting down Symmetra's Sentry Turrets somewhat easy for him.

Due to Roadhog's poor mobility and role as a front line tank, he is not a Teleporter hunter and will rely on his offensive allies to deal with Symmetra's Teleporter ultimate.