Shadow Muk

In Shadow Forme, Muk becomes a good Poison attacker. That said, it's still behind other shadows in this role such as Shadow Victreebel, or even good, old-fashioned Roserade. 

Best PvE Offensive Moveset

• Poison Jab is on par with Acid, the former having higher power, the latter higher energy gain.

• Lick is slightly behind them. What it lacks in damage it makes up for in energy gain.

• Gunk Shot is clearly superior to Sludge Wave, having higher base damage for the same energy cost.

• Infestation and Dark Pulse are more suited towards gym defense.
• Acid Spray is a terrible move in raids.
• Thunder Punch does not synergize well with any of Muk's fast moves, leaving it useless on an attacking Muk.

Best PvE Defensive Moveset

• Infestation is slightly superior to Poison Jab and Acid, offering counter coverage and better energy gain.

• Dark Pulse is a fantastic charge move on Muk, with multiple bars and phenomenal counter coverage.

• Thunder Punch is another fantastic charge move on Muk due to having three bars, a reasonably early damage window, good neutral coverage, and good power.

• Gunk Shot is strong, and it literally throws a garbage can, which is neat.

• Acid Spray is a 3-bar STAB charge move, but its low damage means that it's actually out-damaged by Thunder Punch despite the later not having STAB.

• Both Lick and Sludge Wave are relatively ineffective on defense.