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 Mario franchise, including meeting Wario in Densetsu no Stafy 3.

For more information, see the Starfy article on the Starfy Wiki.