Boo Mario

Boo Mario is a new form of Mario that appears in the game Super Mario Galaxy. As its name implies, the Boo Mario form is Mario disguised as a Boo, although his hat and face remain relatively the same.

In order to change into Boo Mario, Mario must grab a Boo Mushroom. With this transformation, Mario can turn himself invisible and pass through certain walls by swinging the Wii Remote, and levitate by pressing the A button. Mario can attract Boos as well, and use them for various purposes. The transformation is lost if Mario takes damage or passes through a beam of light. Mario first uses this transformation in the Ghostly Galaxy to rescue Luigi. As Luigi's afraid of ghosts, he'll freak out when Mario gets near him in Boo form.