A skeleton. The upper right part of his skull is missing, and his clothes are stained with what looks like blood splatter. He uses an axe as a weapon. He basically always has it with him. He wears a gray hood (usually down), a dark blue hoodie, black shorts with a single white stripe, and pink slippers.

A skeleton. His right eye is red and blue, and his left eye is red. He wears a gray hood (usually up), a dark blue hoodie, black shorts with a single white stripe, and pink slippers. Because he sees hallucinations of Papyrus (his brother), Killer calls him "Hallucination Guy."

A skeleton. A black liquid is constantly dripping from his eyes. He uses a knife as a weapon. He basically always has it with him. He wears a pale yellow hood (usually down), a dark green hoodie, white shorts with a single black stripe, and pink slippers.

A skeleton. His body is black, and blue strings are constantly coming out of his eyes. He uses bones and strings as weapons. He wears a blue scarf, a black hoodie over a red shirt, black shorts with a single blue stripe, and blue slippers.

A skeleton. He has a lightning-shaped scar under his left eye. He uses a giant red sword as a weapon. He basically carries it on his back. He wears a white hood (usually down), a black inner shirt with a white jacket, black shorts with white X marks, and white sneakers.

A skeleton. The left side of his face is covered in slime, and his whole body is black. He uses tentacles and bones as weapons. He wears a black hood (usually down), a black hoodie, black shorts, and black slippers. First person: I (rough, casual) Speech style: Ends sentences with "dana," "nanoka?", "ka," etc. The boss of the Dark AU.