He appears as a boss in Petey's Bomb Battle. The objective of the battle is to defeat Petey Piranha by throwing bombs at him repeatingly, he throws the bombs randomly at any player which they lose points. While enraged, he throws bombs randomly at players twice.
He also appears as a boss in Petey Piranha's Shell Smackdown. The objective of the battle is to grab shells and throw tham at him. If he hits you with his attacks, you lose a point. When enraged, he gains slightly different attacks while bigger shells spawn alongside normal sized ones.