Colin

Colin (うこん) is a character, who appears in Rhythm Heaven Megamix. He, like Tibby, is a guardian and as he gets older he will transform into a palace, like Tibby's Mom.

Story
Colin appear in Rhythm Tengoku The Best Plus Comic 19テビリとウコン (Tibby and Colin), where Tibby says, Colin's stomach look like a door. After this, Colin opens it up for Tibby to see inside.