Boo Buddies

Circling Boo Buddies are a formation of many Boos found only in Super Mario World. They chase and circle around Mario and Luigi, slowing down their process. Touching any single one of the Boos that make up a Boo circle can prove to be fatal for the Mario Bros. The only way to get rid of them was to touch them while they are invincible from a Star or by going to another room. Thankfully, they only appear in small rooms in Ghost Houses. They reappear after an 18 year abscence (not counting remakes) in New Super Mario Bros. Wii. Another similar Boo formation is the Boo Buddy Snake.