Dugtrio

Dugtrio has a strong moveset for PvE, but lacks stats compared to existing powerhouses. After a few years of Pokemon Go, this Pokemon unfortunately doesn't provide much use beyond its dex entry. 

Best PvE Offensive Moveset

• Mud Slap performs the best on offense.
• Mud Shot is a step down in PvE.
• Sucker Punch has no use.
• Earthquake is the strongest charge move for offense. 
• Mud Bomb isn't that far behind, and may have more consistency due to it being a 3-bar move.
• Stone Edge is powerful but lacks STAB and general synergy. 

Best PvE Defensive Moveset

• Mud Slap slaps hard on defense, thanks to its high base power. 
• Sucker Punch is a decent alternative thanks to its relatively neutral Dark-typing.
• Mud Shot has poor defensive damage output. 
• Mud Bomb can be used frequently, making it ideal for defense.
• Stone Edge provides wide Rock-type damage, and is hard to dodge.
• Earthquake is too slow for defense. 

Mud Shot is recommended for its superior energy generation that's needed for Dugtrio's costly charge moves. Mud Slap generates energy much more slowly, and deals superior damage output as a compromise. Sucker Punch sports average energy gains and damage output, but lacks STAB. 

Mud Bomb costs the least amount of energy, gets STAB, and can be used frequently. It is generally more consistent than Earthquake, due to the latter's significant energy demands, though having a powerful KO threat is also quite valuable. Stone Edge is provides wide Rock-type coverage, though it is somewhat costly to use.