Z-moves

[Black117]

To add to what naitre mentioned, Z-Belly Drum fully replenish your HP and isn't tauntable or encore proof, which can be extremely threatening if supported well. Probably the best example of a Z-Belly Drum user is Snorlax as it has high HP and noticeable defenses to survive a double target. By the time the Belly Drum user setups, they'll be at about half HP to use that's the only exploitable thing.