Yvonne Bradshaw is the former headmistress of St. Hilda's School for Girls and the lover of Adam Jacobs. Her father was an unspecified demon and her mother was human, making her a Succubus, a supernatural being that infects men by touch and then kills them by having sex with them (Adam had only survived for as long as he had because he was already dead). She infected Hal and Tom when she came to Honolulu Heights, causing them to experience dreams of having sex with her, making them both so scared they locked themselves in their rooms.