Starfy

Starfy, also known as Stafy, is the main character of The Legendary Starfy series, who has made several appearances in the Super Mario franchise:
 * Starfy, an Assist Trophy in the Super Smash Bros. series.
 * Starfish, an enemy resembling Starfy from Super Princess Peach.
 * Legend of Stafy, a poster seen in the Yoshi Theater in Mario & Luigi: Superstar Saga.
 * Starfy: Prince of Pufftop, a Super Mario Maker level featuring Starfy's Mystery Mushroom costume.

Starfy has also interacted with the Super Mario franchise, including meeting Wario in Densetsu no Stafy 3.