His motivations are to capture a human so that he can become an official member of the Royal Guard, a very prestigious job. He also can open his mouth and has a cyan tongue. UnderSwap Sans is similar to Canon Papyrus in a lot of ways, but there are also some differences! For example, instead of "NYEH HEH HEH!" or "WOWIE!", UnderSwap Sans will say "EH HEH EH!" or "WOWZERS!". Instead of making spaghetti for his friend, he makes tacos(as stated before). Sans still enjoys Puns.