 The scene in which Mongo knocks out a horse has a basis in reality.  Mel Brooks former "Your Show of Shows" and "Caesars Hour" boss,  Sid Caesar, a physically imposing and somewhat violent man, reported  in his 1982 autobiography, "Where Have I Been?" that while trail  riding with his wife, her horse caused trouble and he punched it  once between the eyes. The horse collapsed, unconscious. He notes  that this event was Mel Brooks inspiration for the Mongo vs. horse  scene in Blazing Saddles.