Bill Board

Bill Board is a talking signpost in Super Mario Galaxy. He teaches Mario how to play the Star Roll. He first appears in the Rolling Green Galaxy. He appears again in the Melty Molten Galaxy, and the Rolling Gizmo Galaxy. His last appearance is in the Grand Finale Galaxy, where he comments on how nice Mario's world is, and how he'd be able to enjoy it more if he wasn't a sign. He is presumably related to Gil Board, Phil Board and Jill Board.

Trivia

 * His name is a pun on billboard.