if you mean the fat buu, then it must be Makuhita

Ah, now thatz a challenge

Mewtwo!

I know he ain't no pokemon.. but he's DEFINITELY Kirby.

but he sure LOOKS a lot like makuhita

DITTO! He's a pink blob that absorbs things and becomes like them to take their powers and become stronger! OMG!! Majin Buu was just a mutated Ditto all along! D: *has solved the mystery of life*

I say ditto

I'm not sure which version you're talking about. If its the muscular version of him, then I'd say ditto because they're very similar. But if it's the fat version, then I'd say Snorlax. Both have the same physique, both are hard to hurt, and both are really annoying.