HBO has announced three new casting decisions for the second season of its Harry Potter TV series, filling the roles of a young Tom Riddle (Lord Voldemort) and Dobby the house elf, while also recasting Ginny Weasley after the original actor stepped down. The announcement matters because it fills in key parts of the ensemble ahead of the story's darker turns, and comes as anticipation builds following a new trailer for the first season, subtitled Harry Potter and the Philosopher's Stone.

Billy Barratt, a former International Emmy winner, will play young Tom Riddle, becoming the first actor cast in the role in this adaptation, though the identity of the actor playing the adult Voldemort remains unconfirmed. Lenny Rush has been cast as Dobby, likely to be realised through CG, while Bonnie Hill takes over as Ginny Weasley for season two after Gracie Cochrane departed the role, citing personal reasons in a statement praising her time on the production. The series, adapted from J.K. Rowling's novels and written by Francesca Gardiner, stars Dominic McLaughlin as Harry Potter alongside Arabella Stanton, Alastair Stout, John Lithgow and Nick Frost, and is due to premiere on 25 December on HBO.