This 1975 British comedy film stars Graham Chapman, John Cleese, Terry Gilliam, Eric Idle, Terry Jones and Michael Palin.  It was conceived during the gap between the third and fourth series of their popular BBC television program.  Name this film to be entered in to a drawing for NCG movie passes!

This audio clue of the amazing duel with the black knight should help you get the answer without losing an arm and a leg!