Petey Piranha

Petey Piranha is a large Piranha Plant that has appeared in many Mario titles, though his only 3D Mario appearance is Super Mario Sunshine. He has the ability to spit goop as well as fly and attack with vines.

In Super Mario Sunshine
Petey Piranha is fought at Bianco Hills, the first area of the game. While Mario runs about Bianco Hills, Petey is able to throw goop at him. When Mario actually reaches the top of the windmill where Petey is stationed, the windmill's roof collapses from the plant's weight, beginning the battle.

Petey Piranha can both spit Goop and headbutt Mario if he gets close to him. Mario must spray Petey's mouth with water from F.L.U.D.D., causing his stomach to be filled with liquid. He'll fall over, allowing Mario to run over to him and ground pound his belly. After ground pounding his belly three times, he explodes and reveals a Shine Sprite.

He appears yet again in another level in Bianco Hills where he is essentially fought in the same fashion.

Related bosses
The Mario Galaxy games feature three different Piranha Plants that have similar roles to Petey Piranha. Dino Piranha and Fiery Dino Piranha from the first game as well as Peewee Piranha all bear some resemblance to Petey.