On November 17, 2000, nearly 35 years after the animated special aired on television, Dr. Seuss fans finally got a live-action film adaptation of How the Grinch Stole Christmas. Director Ron Howard transformed 11 soundstages at Universal Studios into the whimsical, glittering world of Whoville, and populated it with an impressive lineup of stars just barely recognizable beneath prosthetic noses and pear-shaped costumes.

Though the movie didn’t achieve overwhelming acclaim at the time—The New York Times called it a “shrill, overstuffed, spiritless cinematic contraption”—Jim Carrey played the grouchy, nihilistic anti-hero with enough gusto to make it an annual must-watch for many. To celebrate its 20th birthday, here are 20 facts about what it took to bring Seuss’s beloved Whos to the big screen.

1. Theodor Geisel’s widow had a very specific vision for How the Grinch stole Christmas.

Theodor Geisel hadn’t licensed much of his work during his life, but his widow, Audrey Geisel, began to open the floodgates after his death in 1991. In 1998, she finally invited Hollywood studios to present her with pitches for How the Grinch Stole Christmas, which would be the first live-action film adaptation of any Seuss story. But she wasn’t planning on leaving the project in any amateur’s hands. For one, the competition was only open to writers and directors who had cashed a million-dollar paycheck from at least one movie in the past. In a letter that laid out all her terms, she also stipulated that she’d only consider Grinch wannabes who were “of comparable stature to Jack Nicholson, Jim Carrey, Robin Williams, and Dustin Hoffman.”

2. Jim Carrey was in character as Andy Kaufman when he first met Audrey Geisel.

Carrey, of course, fit the bill, and Imagine Entertainment’s Brian Grazer and Ron Howard teamed up with him to try to secure the rights. Howard’s idea was to shift the whole “stealing Christmas” debacle toward the end of the film, and focus the bulk of the film on fleshing out the Grinch’s backstory and Cindy Lou Who’s crusade against a consumerist Christmas. Audrey Geisel liked the angle, but it was Carrey who really sealed the deal—even though he was in the middle of shooting 1999’s Man on the Moon and met with her in character as Andy Kaufman.

“Yes, I know it sounds crazy. And yes, I was well aware of how important this meeting with Audrey was. Getting this part was literally a dream come true for me,” Carrey told the Chicago Tribune. “But, she was told in advance that she would not be able to talk to Jim. She would have to talk to Andy.” The only time he broke character was to flash a Grinchy grin, which Audrey told him was “the most impossible smile any human being could generate.” Not long after they parted, Audrey declared Imagine Entertainment the winner of the rights war.

3. Audrey Geisel removed nearly all the adult-themed humor from How the Grinch Stole Christmas.

Audrey Geisel didn’t step aside once the contract was signed. She retained veto power over the film, which she mostly used on the script—all eight versions of it.

“There was much I didn’t like,” Geisel told TIME. Rejected ideas included a stuffed Cat in the Hat hanging in the Grinch’s cave, plenty of bathroom humor, and some sexual innuendo on which Audrey wouldn't deign to elaborate. As she told Entertainment Weekly, “that American Pie stuff has no place in Seuss.” One notable adult-themed bit did make it into the film, whether Audrey realized it or not: A flashback shows a holiday party where Who couples are all tossing their keys into a glass jar, implying that some Whos are swingers.

4. Studio executives were worried Jim Carrey would be unrecognizable as the Grinch.

Perfecting the Grinch’s face took just as much work as writing the screenplay. Special makeup effects creator Rick Baker remembered shooting screen tests for as many as six different Grinch looks, one of which entailed painting Carrey’s face green and doing little else. “I looked like some reject cast member from Cats,” the actor said. While Universal Studios executives were worried that more elaborate makeup would render Carrey unidentifiable—and therefore not worth his $20 million fee—everyone else agreed that the green face paint wasn’t cutting it. To prove that Carrey would still be recognizable beneath a prosthesis, Howard filmed several actors in full Grinch regalia and asked his daughter and her friends to pinpoint Carrey on the tape. “The minute he started moving, they all said, ‘That's Jim,’” Howard told Newsweek.

5. Jim Carrey underwent torture endurance training to help him tolerate the Grinch costume.

The first time Carrey strapped into the yak-hair-covered Grinch costume and matching green facial prosthesis, the process took more than eight hours. “I went back to my trailer and put my leg through the wall and I told Ron Howard I couldn’t do the movie,” he revealed on The Graham Norton Show in 2014. So Grazer enlisted a man who trained CIA agents in torture endurance to give Carrey some distraction tactics. Among them were “eat everything you see,” “smoke as much as you possibly can,” “punch yourself in the leg,” and ask someone to slap you. Carrey took all the advice and even came up with a method of his own: listening to the Bee Gees.

6. A makeup artist took a leave of absence from How the Grinch Stole Christmas because of Jim Carrey's behavior.

According to Baker, Carrey’s makeup process eventually averaged about 2.5 hours for application and another hour for removal—which Carrey had to endure a staggering 92 times. “By the end of the project, literally you could’ve hit me in the face with a baseball bat and I would’ve gone, ‘Good morning, how are you?’” Carrey later said. “I learned patience. It was amazing.” But getting there wasn’t easy. Makeup artist Kazuhiro Tsuji, who would go on to win Oscars for his work on Darkest Hour (2017) and Bombshell (2019), told Vulture that Carrey was so unpleasant and erratic on set that his behavior started to stall production. After discussing the issues with his managers, they decided that Tsuji should take a leave of absence to prove how important he was to the project. It worked: Carrey promised to treat people better, and Tsuji returned to work.

7. Jeffrey Tambor suffered from gout while filming How the Grinch Stole Christmas.

Carrey wasn’t the only actor who despised his Grinchy getup. Jeffrey Tambor, who played Mayor Augustus Maywho, developed gout, which can cause severe joint pain and restrict your range of motion. It would’ve been tough even under normal circumstances, but Tambor faced months of 4 a.m. call times and countless hours in the makeup chair. “There were fake ears, a fake nose, a big rolled wig that looked like a Viennese pastry on my head,” he wrote in his memoir Are You Anybody? "It was torturous."

8. Ron Howard donned the Grinch suit for a day.

The intense makeup process—and all the difficulties that came with it—was such a focal point of production that Ron Howard finally decided to experience it firsthand. Not only did he get decked out as the Grinch, he directed in costume for an entire day. “It must’ve been very confusing for everyone else,” he said.

9. Christine Baranski almost got away with using her own nose in How the Grinch Stole Christmas.

Because Christine Baranski already has an upturned nose, the makeup artists considered letting her skip the prosthetic Who version. After all, her character, Martha May Whovier, is supposed to be Whoville’s most beautiful resident. “But it was a little too real,” Baranski told SouthJersey.com. “I looked like a Who with a nose job—a Beverly Hills Who.” Her 13-year-old daughter Lily was an extra in the film, so the early hours in the makeup trailer became a mother-daughter bonding experience. “We have great memories of going to work together at four o'clock in the morning, having breakfast, and going into makeup. It was something we really shared,’” Baranski said.

10. Ron Howard cast a couple relatives in How the Grinch Stole Christmas.

Another Who extra with notable parentage was Bryce Dallas Howard, daughter of Ron. Bryce, now best known for 2012’s The Help and 2015’s Jurassic World, remembers it as the first gig she ever got paid for. Howard’s brother Clint is also in The Grinch, albeit in a slightly more significant role: Whobris, the ingratiating sidekick of Mayor Maywho.

11. Many of the extras in How the Grinch Stole Christmas were Cirque du Soleil performers.

The background actors weren’t all pint-sized legacy hires. In fact, most of them were Cirque du Soleil performers, who were exceptionally well-equipped to master the zany, acrobatic way of life in Whoville. “The reason we went with Cirque du Soleil performers is because they have all the physical abilities you could possibly need or want, yet they also have a really strong performance background in very odd characters and odd situations—things that are just completely out of the norm,” stunt coordinator Charles Croughwell explained in a behind-the-scenes bonus feature. Since the circus veterans were already accustomed to over-the-top circus stunts, they enthusiastically agreed to try just about anything Howard suggested.

12. The How the Grinch Stole Christmas cast attended “Who School” before they started shooting.

Getting everyone to move in a uniform Who fashion would take some serious work, especially for career actors who didn’t necessarily have experience in such physical roles. So the entire cast attended “Who School,” a few weeks of rehearsing in a studio outfitted with “crash pads, mini trampolines, [and] stunt rigs, so you can get used to all the things the stunt guys are gonna ask of you,” Bill Irwin (Cindy Lou Who’s father, Lou Lou Who) said in an interview. “The Who workers don’t go out with a truck or a crane,” Croughwell explained. “They bounce on this teeterboard and somebody hands them a wreath and they dress it on the building. So it’s unusual things like that—people balancing huge stacks of packages without any effort.”

13. The Whos in How the Grinch Stole Christmas were supposed to sound like upstate New Yorkers.

According to Jeremy Howard, who played Cindy Lou Who’s brother (Drew Lou Who), two key Who characteristics got scrapped sometime between Who School and production. One was a certain way of walking, the other was an accent; Whos were originally meant to sound like they all hailed from upstate New York.

14. Some of How the Grinch Stole Christmas's actors stuck straws up their Who noses so they could breathe.

Jeremy Howard also revealed that most Whos didn’t get to use the same prosthesis every day. “Unfortunately, sometimes the mold I received on a given day would smell like sulfur because it had been at the bottom of the box it was sitting in,” he said. Runny noses, allergic reactions, or just long days on set could make it difficult to breathe, too, so the actors took to sticking straws up their fake noses to help funnel some fresh air into their real nostrils.

15. Second-graders helped out How the Grinch Stole Christmas's costume department.

Since Whos literally wear their Christmas passion on their sleeves, costume designer Rita Ryack thought they’d take the time to make their ostentatious holiday ensembles by hand. She didn’t have Santa’s elves to help her achieve this effect, but she did have the next best thing: children. Ryack enlisted second-graders from a California elementary school to decorate the costumes with classic kid-friendly art supplies. “Anything you see that looks crude and has lots of macaroni and glitter, they made,” she told the Los Angeles Times. Ryack also drew inspiration from 1950s cookbooks to create those unforgettable mug-of-eggnog hats and other culinary-themed costume pieces.

16. Max was played by six different shelter dogs in How the Grinch Stole Christmas.

The canine stars came from Humane Hollywood, an affiliate of American Humane, and trainer Roger Schumacher spent more than three months teaching them certain skills and evaluating their strengths. Of the six mixed-breed shelter dogs that made it big in The Grinch, Kelly and Chip bore the brunt of the stunt work. The other four had their own specialties: Topsy was great at scratching; Zelda was the go-to scooter, Stella did all the barking work; and Bo “pulled” the Grinch’s sleigh.

17. How the Grinch Stole Christmas features some references to other books by Dr. Seuss.

The roof of Whoville’s town center features a massive countdown clock that ticks off the days, hours, and minutes until Christmas. There’s a torch-bearing statue on top, but it’s not shaped like Santa Claus or even a venerated Who from history—it’s Horton, the eponymous elephant from Dr. Seuss’s books Horton Hatches the Egg and Horton Hears a Who! The other Easter egg can be seen at the end of the film, when all the Whos are feasting with the Grinch in his Mount Crumpit cave. Cindy Lou Who passes Max a plate full of green eggs and ham (a nod to Seuss’s book Green Eggs and Ham).

18. Queen Elizabeth II attended the London premiere of How the Grinch Stole Christmas.

The answer to why Queen Elizabeth II would choose to watch an odious green humanoid offend everyone and destroy everything is simple: for charity. The London premiere of How the Grinch Stole Christmas doubled as a benefit for the Cinema and Television Benevolent Fund (now the Film and TV Charity), which helps people working in the entertainment industry. The media didn’t report on the Queen’s reaction to the film itself, but she was all smiles while meeting the cast. And though the meet-and-greet was a rather staid affair, the afterparty definitely wasn’t—Taylor Momsen told Regis Philbin it featured an ice-skating rink, a rock-climbing wall, and a slide with an adjoining ball pit.

19. Mariah Carey co-wrote “Where Are You, Christmas?” for How the Grinch Stole Christmas.

Not long after creating Celine Dion’s “My Heart Will Go On” for 1997’s Titanic, composer James Horner and lyricist Will Jennings teamed up again to write a ballad for The Grinch. After developing “Christmas, Why Can’t I Find You?” for Momsen to sing in the film, they enlisted Mariah Carey to help them flesh out a longer version for the soundtrack. That song was “Where Are You, Christmas?,” which Carey herself was presumably supposed to sing. Needless to say, she didn’t, and the song went to country powerhouse Faith Hill. Why Carey’s deal fell apart is still shrouded in mystery. At the time, her PR representative told People that it was a scheduling issue, but some believed the real reason had to do with her ex-husband—Sony Music executive Tommy Mottola. Carey was still signed to Sony, and People posited that Mottola wouldn’t allow her to record a track for another label. As for whether or not we’ll ever get to hear Carey’s original version of the song, there is hope—she recently told Bravo host Andy Cohen that a demo exists, though she’s not sure where.

20. The How the Grinch Stole Christmas soundtrack features Busta Rhymes, Smash Mouth, and *NSYNC.

Though the soundtrack doesn’t boast a ballad from the “All I Want for Christmas Is You” singer (who’s now been christened the “Queen of Christmas"), several other musicians made oft-forgotten contributions. Smash Mouth’s “Better Do It Right” is all about misbehaving around Christmas, and *NSYNC’s “You Don’t Have to Be Alone (On Christmas)” is all about how you don’t have to be alone on Christmas. Ben Folds, Eels, and Barenaked Ladies also recorded tracks, but the most surprising participant is probably Busta Rhymes. Not only is his “Grinch 2000” backed by a children’s chorus sampling “You’re a Mean One, Mr. Grinch,” it also features Jim Carrey rapping in character.