Boshi

Boshi Munchakoopas (known as Washi (ワッシー) in Japan) is a fictional character in the Super Mario series that only appeared in Super Mario RPG.

Fanon Realm
Boshi is a Blue Yoshi with an attitude problem. He allies himself with Wario, Waluigi, Wapwach and Wadaisy. In the FanonLand realm, Boshi was banished from The Mushroom Kingdom as punishment for his rudeness.

Trivia

 * Boshi is the only Yoshi to go barefoot.
 * His Japanese name (quite literally) is Bad Yoshi (Combining Waru and Yoshi), the very two words combined for his English name.