Green Boo

A Green Boo is a type of Boo found solely in Super Mario Bros. Deluxe. In the You vs. Boo mode, the player will eventually encounter the Green Boo as an opponent in racing. When the player beats the White Boo a certain number of times during a race, it will forfeit. After this, the Green Boo will enter the competition. The Green Boo is slightly faster than the White Boo, and will occasionally speed up greatly during certain parts of the race, giving the player a greater challenge. Once the Green Boo is defeated, the Red Boo will enter the competition.

A similar type of Boo appears in Mario Party DS. These Green Boos appear in the minigame Peek-a-Boo, when the differences between the Boos is in color.