He only kills humans, and will hunt them if they ever fall down here. After many years of hunger Sans is seemingly bored of everything, but it has damaged his psychological state severely, he now enjoys psychological humor. He is sadistic to the bone, no ounce of him is kind. He will kill if he needs to, and does it for fun. He enjoys hearing people scream and cry for mercy. His sanity is gone for starving for years. He is a shell of his former self, a darker and evil person. evil incarnate