The Godfather is rightly considered one of the greatest movies of all time. It was a huge hit at the box office, won Best Picture at the Oscars, launched the career of Al Pacino, and proved that a supporting character can spend an entire film speaking in a ridiculous voice and still win an Academy Award. The film's enduring legacy is only slightly discolored by the fact that, in at least some of those groundbreaking and memorable scenes, the actors aren't wearing any pants.
The horse even insisted on being filmed without them.
Between takes of this ultra-serious mob drama, the cast were goofing off like middle schoolers on substitute teacher day pretty much all the time. One of their favorite running gags was to drop their pants and moon each other. It all started with James Caan and Robert Duvall, who, for some indescribably insane reason, decided the only way to overcome their nervousness about working with the legendary Marlon Brando was to flap their naked ass cheeks at him in between takes, which probably had the screen veteran wondering just what the hell kind of drugs these young Hollywood kids were taking and if they had any leftovers he could buy.
The face of a man that deeply regrets not putting his pants back on before sitting in a chair that Brando had just used.
However, if you're under the impression that Brando was above asinine hijinks, then you have seriously overestimated him. While cameras were being put in place and 500 extras were being assembled for the film's famous wedding scene, Brando took the opportunity to turn around, pull down his pants, and flash his legendary trouser hams to the entire cast and crew. It is up for debate whether his ass or his Don Corleone face looked more like a sad bulldog.
"My God ... it's like one of those paintings where the eyes follow you."
As a reward for this noble (read: unbeatable) act of public exposure, Caan and Duvall presented Brando with a belt that read "Mighty Moon King," which is a great name for a David Bowie album and/or one of Frank Zappa's children. It is unclear whether Brando accepted the belt himself, or if he sent a fake Native American woman to reject it on his behalf.