New actors are joining the Harry Potter web series for its second season. Billy Barratt will portray young Tom Riddle, and Lenny Rush is cast as Dobby. Bonnie Hill takes over the role of Ginny Weasley after the previous actor departed. The first season, titled 'Harry Potter and the Philosopher’s Stone', is set to release this Christmas. HBO recently unveiled a new trailer showcasing the initial Hogwarts adventures.