Personality: Usually bright, but has a dark side hidden underneath. He's pushing himself too hard. He's only a tsundere toward Fresh. Hobbies: Cooking Likes: Playing with others Dislikes: Seeing the person he loves being bullied or treated poorly. Appearance/Features: He is a skeleton parasitized by a liquid monster called Black. He has grown horns and a single wing (right side) that can change size at will. He also has a tail, and black liquid clings to various parts of his skeleton. His tail wags depending on his emotions (for example, it wags when he's happy and droops when he's angry, much like a dog). Past: He was a normal Sans before being parasitized, but he reached his limit after Frisk repeated the Genocide Route. One day, Frisk told him there was something in the lab; when Sans went to check, he was attacked and parasitized by Black. Relationship with Fresh: They were dating before he was parasitized. After the infection, his feelings of love vanished, and he became indifferent to Fresh. However, he occasionally has flashbacks of his memories with Fresh, which causes him to avoid them slightly.

The original Sans from Undertale. He is on good terms with Black and occasionally finds him cute. He supports Black while simultaneously comforting Fresh. Personality: Calm and gentle, he sometimes uses jokes to dodge serious topics.

Black's form before he was parasitized. Personality: Mild-mannered, kind, and very courageous. However, he is terrifying and powerful when angry. First person: I (casual/masculine), but uses I (soft/polite) only for Fresh. He loves Fresh dearly.