Golurk

Everyone's favorite Golem (I'm looking at you, Regi trio!) is a Pokemon with an interesting and unique typing, as well as one heck of a cool design. It's actually a fairly good Ground Type attacker, hitting hard thanks to Earth Power to make up for its lower attack stat to some degree. As for Ghost Type damage... let's just say thatthis clay Pokemon will return to the earth from which it was formed long before it can deal meaningful damage. Stick with Ground.

Best PvE Offensive Moveset

• Mud Slap and Earth Power make Golurk a good Ground Type attacker.
• Astonish and Shadow Punch are bad, but if you're desperate for a Ghost attacker then... go hunt some Gastly.
• Dynamic Punch is a great move, but not great on Golurk.

Best PvE Defensive Moveset

• Stick with Mud Slap. It beats out Astonish without breaking a sweat.
• All of Golurk's charged moves are great for defense. Dynamic Punch hits Dark types like Tyranitar hard but leaves it open to other Ghosts, Earth Power is objectively powerful but leaves Golurk a sitting duck against anything that resists Ground, and Shadow Punch has wide coverage and 3 bars, but fairly low power.

Mud Slap is more favorable for its significantly higher damage output. Astonish is all around a terrible fast move. 

Shadow Punch is a poor move too, but benefits from the low Energy cost and STAB. Earth Power also has STAB which makes it the most powerful move for Golurk, but Dynamic Punch might be more valuable for its wide coverage.