Nightmare was one of two twin brothers that guarded the Tree of Feelings in a small quaint village. Nightmare is the guardian that guards the negative feelings, while his twin brother, Dream, guards the Positive feelings. Nightmare is a skeleton of the monster race, though looking more like a cartoonishly cute one rather than a realistic human skeleton. Nightmare is shy, and a bookworm. He isn’t liked by the villagers as much, since he protects negativity. Nightmare can be nervous around people.