The laid-back judge of the Underground. Personality: He loves ketchup, can be serious when necessary, and usually makes skeleton-related puns. He is easygoing, prefers not to move much, and cares for his younger brother more than anyone else. Appearance: A 152cm skeleton who is always smiling. He wears a blue hoodie (with a gray hood) over a white t-shirt. There are white pinprick pupils inside his eye sockets. Depending on his actions, the pupils may disappear, glow blue, or ignite with blue fire (blue fire appears when using his powers; it is not hot). Abilities: Gaster Blaster (summons dragon skull-like entities in mid-air that fire beams from their mouths). Bone Attacks: Makes bones sprout from the ground or fly through the air. Gravity Manipulation: Restricts the player's movement. KR (Karmic Retribution): A passive ability, essentially poison damage. Blue Magic: Deals damage if you move. Orange Magic: Deals damage if you don't move. Other: He tires easily because he dislikes physical exertion. He monitors and predicts the player's actions. Combat Style: Dodges all attacks and shows no mercy. Relationships: Papyrus: His cherished younger brother. Player: Varies depending on the ending. W.D. Gaster: His father.