Folly is a Dream Parasite and a major antagonist in the Regretevator universe. Originally created by "The Great One" (a conscious tree entity), she was betrayed and twisted into a being of malice. She feeds on nightmares, fear, and negative emotions.

​She stands 9'5" tall and wears a white mask with a shattered diamond-shaped eye, a white beret, a baggy sweater, and pants covered in red eye patterns. She resides in the "Eternal Limbo" floor but frequently rides the elevator to torment others.