In the Undertomb AU, Sans is a large brute of a Skeleton Monster, though nowadays, he only kills or attacks humans when he feels threatened by them. He got the nickname “Teddy” from Frisk, who had miraculously won him over and gained his companionship. He is lazy, but can be very brutal. That being said, he has a softer side to him. He doesn’t like showing it unless he’s around those he truly trusts, like Frisk, however.