Dark Boo

Dark Boos are purple, art-loving Boos that appear in Paper Mario: The Thousand Year Door and Super Paper Mario. They may be found only in the hidden spot of the Poshley Sanctum and also in the Pit of 100 Trials. Dark Boos are more powerful than their white brethren. They return in Mario & Luigi: Partners in Time in the Gritzy Caves area, looking just like before.

Dark Boos resemble Pink Boos from Super Mario Sunshine.

Trivia
It is the only enemy in Super Paper Mario that isn't a sillhouette. The sillhouette form of a Boo is called the Dark Dark Boo.