Sans is a skeleton. He wants to see his role model, Mettaton, in action.
Sans looks up to Mettaton as a hero. He's an innocent monster who assumes an energetic behavior. He's also naive, as well as clumsy, as he trips frequently. He's frightened of Cameron in the Genocide route, after learning her intentions, but stands up to them to protect the Underground, and be like Mettaton.
He has no hair and white pupils in his black sockets. He has a dark ring around his left eye.
He wears a baby blue sweater with oversized sleeves and sapphire stripes. He wears black shorts and blue sneakers.