Tell him Sanji died and cant cook him anymore meat
Blame Usopp
Walk behind him singing loudly I'm a real boy
Ask him if he wished on a star that he would be a real boy
Say Buggy will get to the Grand Line before him
Every time he is about to enter a room run ahead of him and say "The future king of the Navy oops I mean Pirates"
tell him to put a watermelon in his mouth ( after he does this hit him in the back of the head so it get's spit all over the ship
take his hat
throw him into the ocean
after someone gets him out say "oops i thought you were Usopp"
try to stretch him all the way around the world