He speaks few words and wants to avoid people. He's described as rude. He refuses to be in a good mood. Even when he is, it's very rare to see it.
Small human with bright red eyes and a blank expression on his pale-skinned face. A grey/purple thundercloud is usually seen swirling and hovering around his frizzy, lopsided scarlet-red hair (his hair is sometimes seen spiky). He wears a jet-black jumper with dull purple stripes in a similar pattern to Frisk's with a pair of stormy purple-grey shorts and a pair of red boots. (He was originally designed as a cat by Wendy Ann Gardner but it's not certain.)