Dino Piranha

Dino Piranha is the first boss fought in Super Mario Galaxy, being found in the Good Egg Galaxy. Mario crashes into the egg he is being held in, causing his tail to be exposed. If Mario spins and hits his tail, Dino Piranha will break free from his egg.

In Super Mario Galaxy
Dino Piranha fills a similar role to Petey Piranha in Sunshine. When having a more relaxed expression, Dino Piranha is purple with white spots but when angry, he's red with white spots. He can be defeated by spinning his tail, causing it to hit his head. Later in the game, he can be fought at Melty Molten Galaxy as Fiery Dino Piranha, possibly an injured version of Dino Piranha. Strangely, Dino Piranha is seen at the end of the game celebrating the recreation of the Universe.

In Super Mario Galaxy 2
Dino Piranha, along with King Kaliente, Major Burrows, Bouldergeist, and his fiery counterpart appears in the special world of the game as a part of the Boss Blitz Galaxy.