Teen Wolf: Monstrous

"Monstrous" is the tenth episode of season four of the supernatural drama series Teen Wolf and the fifty-first episode of the series overall. It was directed by Russell Mulcahy with a script written by series developer Jeff Davis. It first aired on Monday, August 25th, 2014 at 10:00 pm. In addition to the main cast, notable guest stars for this episode include Jill Wagner as Kate Argent, Ivonne Coll as Araya Calavera, Meagan Tandy as Braeden, Ian Bohen as Peter Hale, Ivo Nandi as Severo Calavera and Ian Nelson as Derek Hale, who has been regressed in age to that of a young teenager. Whaaaaaat?