Fans of the classic film The Godfather were stunned to realise how Marlon Brando achieved the iconic "bulldog" look for his character.

Brando, who won Best Actor at the for his portrayal, has gone down in history as one of the best actors of all time. His performance in The Godfather is often cited as a career-best moment for the star, whose speech style and facial appearance stunned viewers.

Those who love the classic, which came out in 1972, are only just finding out how Brando achieved the look, with his seemingly swelled jaw, a choice made by the actor during rehearsals. A post to the r/MovieDetails subreddit has since seen fans praise Brando's commitment to the role.

His additions when rehearsing the role were kept and modified into a special prop which you cannot see in the film, but the effect of the tool is legendary.

The Reddit thread post reads: "In The Godfather (1972). Marlon Brando wanted Vito Corleone to look like a bulldog so he stuffed his cheeks with cotton during rehearsal, however in the actual movie he wore special dentures."

Those special dentures gave Brando's jaw a more pronounced look, making the actor, who was just 47-years-old at the time of making the film, look that much older.

Fans were thrilled by Brando's dedication and pointed out Robert De Niro, who portrayed Brando's Vito Corleone in The Godfather: Part II, had a similar denture fitted to keep the look.

One user wrote: "Robert De Niro had a smaller version made to wear in Part II." Those who had not noticed the prosthetic on either man on a first viewing were blown away after realising a prop had been used for the iconic look.

A stunned fan commented: "Dude how did I not notice this? F***ing blew my mind." One user suggested the prosthetic was a choice made by Brando. They wrote: "It's just how Brando envisioned Vito Corleone. It makes him look older and sterner."

Brando's on-set antics stretched far beyond cotton balls in his mouth, as one fan recalls the actor tying heavy weights to himself to prank other cast members who were meant to carry him up a flight of stairs.

They wrote: "In the scene where He is getting carried up the stairs after being shot, he hid weights under him so he could prank the other actors."

Brando's all-time great movie acting performance had a few wild moments too, with the iconic cat perched on his lap a total accident.

A stray had been wandering around the set, and according to various sources, both Brando and film director Francis Ford Coppola believed it would be the perfect addition to the scene.