John Cleese, who turns 61 on Friday, has joined the movie cast of “Harry Potter and the Sorcerer’s Stone,” based on the J.K. Rowling bestseller, which is currently being shot in England. Variety says that the former “Monty Python’s Flying Circus” and “A Fish Called Wanda” writer and star will play Nearly-Headless Nick — aka Sir Nicholas De Mimsy-Porpington — a pal of Potter’s who lives as a ghost in Gryffindor Tower. (NHN earned his nickname when an attacker didn’t quite succeed in beheading him.) The “Harry Potter” movie, being directed by Chris Columbus (“Mrs. Doubtfire”), is due to be released toward the end of next year.