Fluffy the Dolphin

From the Super Mario Wiki

Fluffy the Dolphin is an enemy that battles Wario along with Stuffy the Dolphin in Wario: Master of Disguise. He is a young Dolphinian with succesion rights to the throne. They accompany Stuffy by shooting balls of energy at Wario. They can be defeated by Cosmic Wario, or another disguise that can attack. They only appear in Blowhole Castle, obviously. The enemy glossary says to except a firce regicide when the magic day finally comes.