horror sans is very unpredictable and unstable.while error is playful and selfish.Killer Sans is very thoughtful but not to the point of feelings usually killing most of the time, hates being belittled, and generally is a negative character, although killer loves bunnies and had two cat's before Nightmare killed one and nightmare is sadistic and cross is a bit aggressive and a little selfish And they are vampires,they are all boys too dust is quiet and don't talk much and depressed