That guy who can kick your ass anyday when he feels like it/when he's not hungry(never)/make fun of him/make fun of his friends/pee in his eye.
Oh, and he'll become king of the pirates. Don't belive me? Go ask the 500+ people who's ass he kicked.
"Shit, I wanted to become king of the pirates, then Luffy totally just shoved a wooden board up my ass."