King Boo is one of the last bosses in Super Mario Sunshine. 

Which is a little amusing since he was the final boss of Luigi’s Mansion. So him and Mario have already met once. 

This one is on a big roulette-like wheel. You have wait for him to spit out some spicy peppers instead of enemies. 

And then hit him with something like a pineapple. 

Probably one of the tougher battles in the game but I enjoyed it.