Here's everything to know about HBO's 'Harry Potter' series, which may have recently cast its new Dumbledore After seven books, eight movies, one play and a whole spin-off series, Harry Potter is debuting on the small screen for the first time.

It seems John Lithgow spilled the (Bertie Bott's Every Flavor) beans about his involvement in HBO's in-the-works 'Harry Potter' series. 'A total surprise to me,' he says.

John Lithgow has confirmed that he will portray the Hogwarts headmaster in HBO’s upcoming “Harry Potter” series, which will begin filming this summer. Lithgow, 79, said in an interview with ScreenRant that the invitation to play the beloved character came “as a total surprise.”