There are some actors who never manage to get the leading role in a movie, or headline a major film series, but still attract scores of fans through decades of hard work.

Sadly, one of those legendary stars has just passed away.

According to R. Lee Ermey's manager, Bill Rogin, the actor passed away from complications of pneumonia on Sunday.

At 74, even after appearing in dozens of films, Ermey is still best remembered for his breakout role as Gunnery Sergeant Hartman in 1987's Full Metal Jacket.

A one-of-a kind career

Ermey could talk the talk in Stanley Kubrick's classic Vietnam War film, because he had actually walked the walk.

As a child, Ermey was a bit of a delinquent. At age 17, a judge gave him the choice of joining the military of going to jail.

Ermey signed up for the Marine Corps.

He went on to serve in both Vietnam and Japan, before an injury in the line of duty removed him from active service.

Ermey's no-nonsense disposition made him a perfect drill instructor, and he trained Marine Corps recruits in San Diego.

But as Ermey's military career was winding down, he set his sights on a new profession: acting.

The role of a lifetime

Ermey studied drama in the Philippines, and found work as an actor in Hollywood films about the Vietnam War - a real soldier playing pretend.

He also worked as a technical adviser on war films, including Apocalypse Now, which helped him land a job with the legendary director Stanley Kubrick.

Ermey was slated to be the technical adviser on Full Metal Jacket, and was given a small part in the film.

But the former drill instructor had his heart set on playing Gunnery Sergeant Hartman, the movie's foul-mouthed drill instructor.

Ermey recorded an "audition tape" for the director, which included footage of him running extras through drills, shouting at them, and reciting the character's opening monologue from memory as actors pelted him with tennis balls.

The unusual tryout earned him the part, but that was only the start of Ermey's impressive career.

"Here, you are all equally worthless"

If you loved Ermey's performance as Gunnery Sergeant Hartman, prepare to be even more impressed.

Ermey actually rewrote most of the film's first half, saying that the early script was "rubbish" and that Hartman did not act the way a real drill instructor would.

Even Kubrick admits that Ermey wrote "about 50% of his own lines," including "about 150 pages of insults."

Some of Hartman's most famous lines, including, "What is your major malfunction?" are still familiar for people who haven't even seen Full Metal Jacket.

And Ermey was nominated for a Golden Globe for his intense performance.

Sadly, Ermey would never have another role as juicy as his breakout performance again.

No such thing as a small role

Ermey performed in dozens of film throughout his career, as well as on a number of TV shows.

He was usually typecast as a tough guy cop, soldier or villain, including in films like Se7en, On Deadly Ground, and The Texas Chainsaw Massacre.

But you may be surprised to learn that Ermey also had family-friendly roles, as a voice actor for cartoons like SpongeBob SquarePants.

Ermey even played a character in all three Toy Story movies. He was - of course - the green plastic army man, Sarge.

At the end of his career, Ermey also hosted a number of military-themed reality shows, including the History Channel's Mail Call, Lock n Load with R. Lee Ermey, and GunnyTime.

He even spoofed his tough guy persona in a hilarious Geico ad, where he played a therapist.

As news of Ermey's passing broke, his famous co-stars paid their respects to the veteran and actor.

Tributes for the Gunny

Even in tributes for Ermey, his most famous role took center stage.

While Ermey retired as a staff sergeant in the Marine Corps, he was later granted the honorary title of gunnery sergeant, to match his character from Full Metal Jacket.

The actor has had the nickname "Gunny" ever since.

Tributes also include the Marine Corps motto, Semper Fidelis, which means "always faithful."

In a tweet, the U.S. Army wrote, "We are grateful for your service to our country and for supporting our service members. Semper Fi."

Ermey's Full Metal Jacket costars, Matthew Modine and Vincent D'Onofrio, shared their own messages in honor of the late actor.

"Do not go gentle into that good night. Rage, rage against the dying of the light. RIP amigo," Modine wrote, before signing off as his character from the film, private Joker.

"Ermey was the real deal," D'Onofrio said in his tribute.

"The knowledge of him passing brings back wonderful memories of our time together."

Even WWE superstar John Cena remembered the late actor, sharing a still of Ermey in Full Metal Jacket with his Instagram followers.

Which of Ermey's movie roles was your favorite?

[H/T: The Hollywood Reporter]