Image Credit: Aidan Monaghan/HBO HBO is pulling off a magic trick with its upcoming television adaptation of Harry Potter. Now that the famous Wizarding World is coming to the small screen, fans have learned who will be playing some of the adult characters at Hogwarts. "We are happy to announce the casting of John Lithgow, Janet McTeer, Paapa Essiedu, Nick Frost, Luke Thallon and Paul Whitehouse to play Dumbledore, McGonagall, Snape, Hagrid, Quirrell and Filch," showrunner and executive producer Francesca Gardiner and director and EP Mark Mylod said in a statement.