Animal Rights groups complained about it. Cast and crew complained about it. Nevertheless, the legendary scene with the horse head remains one of the top-of-the-line movie scenes for fans and foes alike.
It’s practically synonymous with the film, and it’s the easiest way to invoke the spirit of the film. Yet the scene almost didn’t make it into the finished product. Among the people who didn’t like the scene at first was Coppola, who thought the book’s presentation of the scene wasn’t very good. In the end, he found it too good to leave it out.
Line!
Marlon Brando has plenty of eccentricities. One of them is he hates memorizing lines and required cue cards to be in sight at all times so he could get his lines right.
These cards were often hidden behind props and sometimes were even sewn into the clothing worn by Brando's castmates. The reason Brando didn't like to memorize lines is that he thought it ran counter to his method of acting. He wanted an off-the-cuff feeling for this powerful character, and a rehearsed feeling wouldn't give the character the savoir-faire and easy power Don Vito should have.
The Man and the Moon
It may come as a surprise when you find out that the actors spent a lot of time mooning each other. This was just one of the dozens of pranks and gags pulled in order to break up the tension of the movie, and it became the go-to gag.
Actors and crew got used to peeking around a door and checking for a bare bottom. Who was the best at this juvenile act? Brando, who thanks to his heroic efforts furthering the craft was nicknamed “Moon Champion” – he even got an honorary leather belt for his prank efforts.
Frank and Johnny
It's often thought that Johnny Fontane, the singer who shows off at Connie's wedding, was based on Frank Sinatra. It had long been rumored that Sinatra had used his mob ties to go from music to movies.
Sinatra wasn't a fan of Johnny Fontane, and it led to a public confrontation with Mario Puzo, calling him names and threatening to beat him up. It's thought that Fontane's role in the film version of "The Godfather" was much smaller than the book because of this.
The Bulldog's Resurgence
The movie led to a huge comeback for Marlon Brando, as during the sixties most of his movies had failed in big ways. In fact, by the time of "The Godfather", his flops outweighed his successes, and most movie studios considered him a risk. Still, he became the patriarch of the Corleones, and his star rose again, leading to roles in movies such as "Last Tango in Paris", "Apocalypse Now," and "Superman".
The role also landed him an Oscar, and though he would still end up being hard to work with, most famously for "Apocalypse Now", he brought immediate star power.