The earliest horror films were Gothic in style and featured supernatural elements like vampires, ghosts, monsters, and demons. Horror films developed from folktales, myths, ghost stories, and Gothic novels. Some influential supernatural horror films that exemplify the genre include The Exorcist (1973) about a girl possessed by a mysterious entity, The Poltergeist (1982) about a family haunted by playful ghosts that turn menacing, and A Nightmare on Elm Street (1984) about a serial killer who kills his victims in their dreams.