Muk

Stench
Decreases wild encounter rate.
Sticky Hold
This Pokémon's item cannot be removed. Increases chance of encountering Pokémon while fishing.
Type Tier
Poison UU
Statistics
Min- Min Max Max+
HP
105
- 351 414 -
Atk
105
221 246 309 339
Def
75
167 186 249 273
SpA
65
149 166 229 251
SpD
100
212 236 299 328
Spe
50
122 136 199 218
Name Item Ability Nature

Curse

Black Sludge Sticky Hold Careful
Moveset EVs
~ Curse
~ Gunk Shot / Poison Jab
~ Brick Break / Fire Punch
~ Explosion / Payback / Shadow Sneak
252 HP / 80 Def / 176 SpD

This evil blob of venom can take hits on the special side quite well thanks to a healthy base and a good EV apportionment. Just take care to avoid Psychic and Earth Power while building up your Attack and Defense, and then fire off Gunk Shots, and pray they don't miss. If you're not into praying you can use Poison Jab, which is a lot weaker but more reliable. Brick Break is mostly for Tyranitar and assorted Rocks and Steels, such as Aggron, whereas Fire Punch covers Bronzong and Skarmory more effectively and also hammers Toxicroak, who will be smirking at everything else. Speaking of smirks, Gengar and other Ghosts will haunt Muk when he's not using Shadow Sneak or Payback. Both work well with Curse as the Speed drop means Muk will be going last and powering Payback up to 100 if attacked, while Shadow Sneak bypasses Muk's slowness and hits those irritatingly speedy Ghosts and Psychics. Of course, the grand finale is an Explosion boosted by Curse, which requires you to give up some type coverage but is incredibly tempting nonetheless.

You can play around with the last two slots a little. If you have a method of getting rid of Steel or Rock-types (Dugtrio, Magnezone, Probopass), then feel free to use a Dark or Ghost attack in the third slot and Explosion in the fourth. If you have a Pursuit user waiting in the wings to off those pesky Ghosts, then you can stick with Brick Break or Fire Punch to dispose of Rocks and Steels.

You could use Rest, but Muk's weaknesses rarely let him get away with that and it just makes type coverage an even bigger issue.

Name Item Ability Nature

Choice Band

Choice Band Sticky Hold Adamant
Moveset EVs
~ Gunk Shot / Poison Jab
~ Explosion
~ Payback / Shadow Sneak
~ Focus Punch / Brick Break
224 HP / 252 Atk / 32 Spe

Predict correctly and let Muk's toxin fists do the dirty work. A STAB move and Explosion are obligatory, but the last two slots are up for grabs. Most of the time, you will be predicting Muk's counters and using the last two moveslots, saving Explosion until you feel that Muk's usefulness is up.

Name Item Ability Nature

Versatility

Black Sludge Sticky Hold Brave
Moveset EVs
~ Gunk Shot / Poison Jab
~ Focus Punch / Brick Break
~ Shadow Sneak / Payback
~ Giga Drain / Fire Blast
252 HP / 68 Atk / 188 SpD

Basically, this covers variations on above sets without Choice Band or Curse. This is an all-out attacker Muk, where you basically fill in the slots besides obligatory STAB. The special attacks in the last slot are for type coverage, and depend mainly on the tier you are using Muk in. Giga Drain is the superior choice in UU as it can 2HKOs the likes of Quagsire, Golem, and Relicanth. However, in OU competition you may prefer Fire Blast to take out Skarmory, Forretress, and Bronzong. Explosion isn't here but it is obviously an option as well. You can mix and match Muk's moves to your heart's content, really.

Other Options

Fire Punch has been mentioned, but Muk also has access to the other two elemental punches. Ice Punch is your only hope against Garchomp and Gliscor, and it helps against Nidoking and Nidoqueen. ThunderPunch helps a ton against Gyarados and Tentacruel and ties Fire Punch in power against the feared Skarmory. Memento is an extremely unorthodox move that Muk can employ in some very circumstantial cases to set up your next Pokémon, such as a Belly Drummer or some other late-game sweeper. Mean Look can force something to stay into you so you can go kamikaze on them. This pool of dirt can make an acceptable Hazer in a pinch, but don't expect too much mileage out of it unless you're facing a buttload of Ninjask...in which case you're better off picking Weezing. Thief is worth it if only for laughing at your opponent that he will never ever get his item back thanks to Sticky Hold, and Protect sees what your opponent is scheming. Taunt is OK since it stops stuff setting up and forces Ghosts to attack so you can hit them with Payback, and prevents them from burning Muk. Screech can telegraph a switch, sometimes allow Muk a free Focus Punch. Again, Giga Drain is there, but only if you want to surprise enemies that have a 4x weakness to it (Swampert, Omastar, Golem, Quagsire, etc.).

EVs

Muk has three main stats: HP, Attack and Special Defense. Basically, if you want him to hurt things, concentrate on Attack, and if you want him to prevent things from hurting him, concentrate on the other two. The nature should reflect that, be it Adamant or Careful. The 32 Speed EVs on the latter two sets are there so he can Explode on -Speed Swampert without having to suffer an Earthquake first, but that's really where it ends. You probably don't want to use that on the Curse version for obvious reasons. Use a Brave nature for the Versatility set, so your special attack of choice has sufficient power to score some important 2HKOs.

Opinion

Muk is probably one of the worst cases of moveslot syndrome in history. His main offensive type is rather pitiful: Steel, Rock, and Ground are three omnipresent types and none of them mind it. This means Muk relies a lot on his big movepool to really hurt whatever switches into him, but the limit of three leftover moveslots hinders him greatly, especially since Explosion is such a tempting move, leaving him with only two moves for make up for the bad STAB. Muk's main change when getting Pal Parked is over is that Sludge Bomb becomes special, making his only good physical STAB the inaccurate and somewhat exclusive Gunk Shot (which is very similar to Blizzard and Focus Blast) and Poison Jab. Now, Poison Jab is only 10 less base power compared to the old Sludge Bomb, so it's not a very big loss. Nonetheless, Muk did not need any nerfings.

Long story short, Muk has a shot in the Diamond/Pearl standard metagame if you're lucky enough to pack the right moves. If Muk blows up on one opponent, he's done his job. In UU, he's quite a lot more valuable as a special wall of sorts, and is capable of dishing out pain with 105 base Attack.

Counters

As mentioned before, Muk has most trouble fighting Steel, Rock, and Ground-types in general. Muk's list of common counters is insanely long. Tyranitar absorbs it all without any trouble (except Fighting moves) and hits you hard, whether with his STAB moves or with Earthquake. Skarmory is a prick even if you've got Fire Punch, but especially without, as he'll set up Spikes or Stealth Rock on you and blow away Curses if you try to set these up—Fire Blast can 2HKO the tin bird though. Forretress can't blow Muk away and hates Fire moves, but he will set up on him for free if he lacks the blaze. Claydol is weak to Dark and Ghost but does very well otherwise with either Earth Power, Psychic or Earthquake. Donphan, Swampert, Rhyperior, Gliscor, and other defensive Grounds take hits like a champ whatever Muk does and Earthquakes him in the face. Any Steel-type is immune to Poison, so bringing in these requires Muk to resort to other moves, and if he doesn't have the right one he's screwed. This can work in your advantage if you're using Magnezone, Empoleon, Heatran, or any Steel-type really. Really, even if you for some reason aren't using any good defensive Poison resistance, Muk dies to STAB Psychics and Earthquakes from faster Pokémon if he's a bit dented, so you'll be in no trouble.

In UU environment, however, there are fewer safe switches. Quagsire, Whiscash, Golem, or Gastrodon all work fine—the best Muk has against them is Giga Drain. Focus Punch might hurt a tad though. Nidoking and Nidoqueen are in better shape here, thanks to their resistance to Fighting, neutrality to Grass and quad resist to Muk's STAB attacks. Solrock and Lunatone will work as well, with Earthquake, Psychic or possibly Reflect. Aggron, Probopass, and Bastiodon should beware of the same Fighting moves Tyranitar fears so much, but do great for the rest. Ghosts like Rotom and Drifblim can get in any attack that isn't super effective and scare Muk away with the threat of Will-O-Wisp.