Jim Carrey almost quit The Grinch and gave back $20,000,000 paycheck

The Grinch simply wouldn't be The Grinch without Jim Carrey - but it almost was.

The 63-year-old actor well and truly embodied the role of the grumpy green character in the 2000 comedy movie and it's stuck around as a firm fan favourite, more than two decades on.

If you've somehow never seen the iconic movie, aka you've been living under a rock, Carrey plays a grouchy recluse living on Mount Crumpit, who despises Christmas and the joyful residents of Whoville.

The heartwarming family film sees him befriend a little girl called Cindy Lou Who (Taylor Momsen), who hopes to make him fall in love with the festive holiday.

However, it's now been revealed that behind the scenes, Carrey wasn't quite the hilarious character portrayed on screen and he actually tried to quit during filming.

In a new interview with Vulture, the actor explained how his transformation into the fantasy character was less than comfortable.

The Grinch is a Christmas classic with Jim Carrey portraying the iconic titular character (Archive Photos/Getty Images)

He explained that the iconic suit was made of 'unnervingly itchy yak hair' that 'drove him insane all day long'.

Not to mention ten-inch-long fingers, so Carrey couldn’t scratch himself or touch my face or do anything, teeth that he 'had to find a way to speak around' and contact lenses that 'covered the entire eyeball' meaning the actor could only 'see a tiny tunnel' in front of him.

Ron Howard, the movie's director explained: "Some people, when they learn to scuba dive, find that they just can’t wear a mask underwater. A kind of claustrophobia kicks in. And I think for Jim, the contact lenses were doing that."

Speaking about the experience in his own words, Carrey said: "I’d be on top of a 50-foot mountain walking around with this ridiculous costume on and hoping I don’t go off the edge accidentally.

"At the same time, I had to give the audience a sense that, 'Hey, he’s having fun in that thing, and we’re going to have fun with him'. There was a certain buoyancy that had to come with the character."

However, it was Carrey himself who suggested on going all the way with the costume, despite producers offering to do the green eyes digitally.

It turns out the role came along with a lot of problems in the costume and make-up department (Gilbert Flores/Getty Images)

Producer Brian Grazer explained: "We said we could do the green eyes digitally. He didn’t want to do that. He wanted to have green eyes. They were like Frisbees in his eyes. He was in so much pain."

Carrey agreed it was something that he asked for and 'can't blame anyone for'.

Things got worse when Carrey 'started having panic attacks'.

Howard recalled: "I would see him lying down on the floor in between setups with a brown paper bag. Literally on the floor. He was miserable."

The actor said: "The first day in makeup took eight hours. And I went into the trailer and asked Ron and Brian to come in, and I told them that I wouldn’t be able to do the movie and I was quitting."

Howard confirmed that Carrey seemed 'sincere' and 'ready to give his $20 million [salary] back'.

The contact lenses in particular were an issue (Archive Photos/Getty Images)

So why he didn't he quit? Well, Grazer actually found a guy who trained the military 'on enduring imprisonment and torture' to spend time with him.

Carrey admitted: "He gave me a litany of things that I could do when I began to spiral. Like punch myself in the leg as hard as I can. Have a friend that I trust and punch him in the arm.

"Eat everything in sight. Changing patterns in the room. If there’s a TV on when you start to spiral, turn it off and turn the radio on. Smoke cigarettes as much as possible."

He later found out that the man that trained him to 'endure the Grinch' also founded SEAL Team Six - an elite US military special missions unit.

So there you have it, you'll never watch The Grinch the same way again!