First, there were the Italian-American groups, but then came the animal rights activists. They had a big problem with the horse head scene, which anybody should have been able to guess.
Coppola thought it was somewhat hypocritical since lots and lots and lots of people were killed during the movie. Coppola even said outright: “When the head arrived, it upset many animal-loving crew members, who liked little doggies. What they don’t know is that we got the head from a pet food manufacturer who slaughters two hundred horses a day just to feed those little doggies.”
The Cat Almost Needed a Credit
The cat that ended up in Brando's lap really seemed to be enjoying itself. It started purring so loud thanks to the affection Brando was giving the microphones pick it up. It even made some of Brando's lines inaudible!
Brando had to go in later and redub them, and it's possible to still hear the cat purring during the scene. The cat ended up working in the movie's favor since while the Don is dishing out hard statements and intimidating people, he's also proving he has a softer side.
Just Like During the War
A great deal of "The Godfather" is set during or just after World War II. This means several things had to be done to make fashions, details, and even cars look right for the era. In particular, the cars in the film all featured wooden bumpers.
To help the war effort, most cars during World War II donated their chrome to the military and replaced them with wood – it didn't do as much to protect the car in the event of crashes, but with a little bit of paint they look pretty much the same.
Say My Name
As time goes on in the film, Michael Corleone gets married and has a son. The son's name is Anthony, and so is the young actor who played Anthony. This is because the young man didn't have the wherewithal to respond to a fake name, and the other actors with him, including Al Pacino, could only get his attention by calling him by his real name.
It's really no surprise – when any of us were three years old it would probably be impossible to do anything like acting and even respond to a name we didn't recognize.
The Prince of Darkness
One of the memorable visual aspects of "The Godfather" is the shadowy way in which it was shot. Gordon Willis did this in order to produce an aura of darkness around the violent and dangerous Corleone family and the death that both follows and comes from them.
When Coppola and Willis showed Paramount Pictures the finished film, the executives thought it was too dark, not thematically but visually – this led to a long discussion between Coppola, Willis, and the execs about the artistic merit of the choice. Paramount relented, but it earned Willis a nickname: “The Prince of Darkness.”