Disappearing Boo Buddy

Disappearing Boo Buddies are special Boos found only in Super Mario World and Yoshi's Story. They are mostly served as background props and some occasionally swoop at Mario or Luigi. They are found in the long room in Donut Ghost House and an underwater part of the Sunken Ghost Ship and cannot be defeated. They can be effectively avoided by running quickly across the room.

A group of small Disappearing Boo Buddies also appear in the Ghost Castle of Yoshi's Story. These tiny ghosts will swoop at Yoshi very rarely, unless he throws an egg at one of the members of the group. Then, all of the Boos will stop in their tracks and swoop at Yoshi. It is impossible to kill all of the Boos, as more will just appear off-screen.