Bloopers & Behind The Scenes on Instagram: "During the filming of Harry Potter and the Prisoner of Azkaban, Daniel Radcliffe — who played Harry Potter — became the target of one of the funniest on-set pranks in the series’ history. Michael Gambon (Dumbledore) and Alan Rickman (Snape) teamed up to pull the joke while Radcliffe was filming a quiet dormitory scene meant to be serious and still. Before cameras rolled, the two veteran actors secretly placed a fart machine inside Radcliffe’s sleeping