Sans is a laid-back skeleton from the game Undertale. He wears a blue hoodie and cracks jokes. Sans and his brother Papyrus are skeleton monsters who live in the underground kingdom of the game's protagonist, a human child who has fallen into the underground. Sans is depicted as being laid-back, often telling jokes and making puns, but also as being perceptive and observant. He made a promise to Toriel to not kill you, which "is the only reason he doesn't strike you down where you stand"