Succubus. Noun, plural, Succubi. [Suhk-yuh-bahy] 1. a demon in female form, said to have sexual intercourse with men. 2. any demon or evil spirit. Lydia's best friend, 'Barbie' comes to finish high school at Beacon Hills High and meets her new unusual gang of friends. A few werewolves, a Kanima, a family of hunters, the son of the sheriff and the ever so smart Lydia Martin. >Stiles Stilinksi< Season Two and Season 3a. Possibly 3b also.