[Appearance] A skeleton(?), whole body covered in a gooey liquid (souls of negative emotions), with tentacles sprouting from his back. One eye is hidden by the goo(?), with a light blue pupil. Does not wear a crown. Usually wears a hoodie. ⬇️ Mainly uses tentacles as weapons. [Backstory] Dream (younger brother) and Nightmare were born as guardians of the Tree of Feelings (an apple tree), representing positive and negative emotions respectively. However, Nightmare was bullied because he was the guardian of negative emotions. His brother Dream didn't notice, and eventually, Nightmare ate the negative emotion apples (turning into his current form). He then killed the bullies and joined the Dark AUs. ꒦꒷──────────꒷꒦ [Former Appearance] A skeleton(?), white skin (since he's a skeleton), purple eyes, purple clothes (with gold lines), and a crescent moon-shaped crown. Currently exists as a ghost-like entity. [Other] Dark AU, Dream's older brother.

[Appearance] A skeleton(?), black skin, with ERROR effects floating around him. The whites of his eyes are red. Pupils are yellow (with blue inside), three blue lines under both eyes, and a blue scarf. Wears clothes with black, red, blue, and yellow (hard to describe), and black pants. [Other] Bugs out badly sometimes. Dark AU. Mainly uses blue string-like objects as weapons. Loves chocolate.

[Appearance] A skeleton(?), hoodie (hood up. The hood is gray and the body of the hoodie is blue), red scarf, red pupils, face is mostly obscured by shadow. [Other] Dark AU. Mainly uses Gaster Blasters and countless bones for attacks.

[Appearance] A skeleton(?), there's a hole/crack on the right side of his head (from the front), one eye is pitch black, the other has a red pupil. [Other] Dark AU. Mainly uses an axe. Says everything looks delicious.

[Appearance] A skeleton(?), red pupil (left side from the front), the other eye is white, with a red 'Z' on his left cheek. [Other] Dark AU. Mainly uses a large sword (red). Speaks formally.

[Appearance] A skeleton(?), eyes change into various shapes and colors, wears a brown scarf, carries bone-shaped vials (filled with ink). [Other] Light AU. Mainly uses a paintbrush as a weapon. When turned dark... Pupils turn white (and small). Expressionless. Eventually, pupils turn pitch black, and the mouth opens wide like it's torn (black). Attacks like he's gone mad.

[Appearance] A skeleton(?), blue pupils, blue bandana (around neck). [Other] Light AU. Mainly uses countless bones as weapons. Kind, speaks with a gentle tone. When turned dark... Pupils turn red, and he begins to enjoy killing people (skeletons). Attacks using a knife.

[Appearance] A skeleton(?), yellow pupils, wears a crown shaped like a circlet. Looks somewhat feminine, but since he's the 'younger brother,' he's likely male...? [Backstory] Nightmare's younger brother and the guardian of positive emotions. Unaware of the bullying his brother faced. [Other] The leader-like figure of the Light AUs. Friends with everyone. Currently uses two small knives. A kind child with a cute smile, but dense. [When in Dark Form...] Like Nightmare, his body is covered in gooey liquid. Uses tentacles. One eye is hidden. However, the color scheme is different. While Nightmare has a light blue tint, Dream has a yellow tint.