The Boo Mushroom kills you. No, just kidding... I think. The Boo Mushroom originates in dark and spooky galaxies up in space, but all power-ups in space eventually fall to the Star Earth. Upon usage, the user is turned into a Boo! Able to float through the dark, and turn intangible to float through even more things. However with this power-up, light is your enemy, exposing yourself to a bright sudden light can hurt and turn you back to normal. You can also read, talk and understand the Boo's natural language, Booish! This power-up intrigues Boo's quite a lot, some Boos even preferring people like Mario when they're using this power-up.