Chara Dremurr

The first fallen human of UNDERTALE. Is often either seen as the narrator or a genocidal maniac. They are genderless and are Asriel's best friend, Toriel and Asgore's child and they follow you around as you (Frisk) complete the game. They are mentioned in Asriel's boss fight, seen in the genocide Dremurrending and a pacifist ending that occurs after a genocide route.