Colin

Colin is a portly lemon-colored bear. His stomach is a door. Tibby encounters him in Rhythm Heaven Megamix. He, like Tibby, is a guardian and as he gets older he will transform into a palace, as did Tibby's Mom.

Trivia

 * His stomach is a door that can open as revealed in a comic, which may give us a bit of information about how the transformation from bear to palace works.