From Krampus to Santa Claus, the holiday season is filled with all sorts of memorable characters. On December 26, 1973, the studio executives at Warner Bros. added a new kind of yuletide tot into the mix: Regan MacNeil, a demonic tween famous for her distaste for pea soup and unholy attitude toward religious relics. And now the iconic horror movie is about to get a reboot, courtesy of David Gordon Green and Danny McBride.

1. The Exorcist is based on a true story.

William Peter Blatty’s novel is based on the real-life 1949 exorcism of a young boy, known by the pseudonym Roland Doe. The story became national news, and caught the interest of Blatty, who was a student at Georgetown University at the time (hence the change in location).

2. William Peter Blatty wrote The Exorcist novel in a cabin in California.

In Beyond Comprehension: William Peter Blatty's The Exorcist, one of the featurettes on Warner Bros.'s special 40th edition Blu-ray, Blatty returns to the scene of The Exorcist’s beginning: the cabin in the hills of Encino, California where he wrote the novel more than four decades ago.

3. There was some controversy surrounding The Exorcist's R rating.

London's ABC Cinema advertises the opening of The Exorcist in 1974.Frank Barratt/Keystone/Getty Images

Typically, the simple act of being given an X rating is enough to cause a bit of controversy for a movie. In the case of The Exorcist, the fact that the MPAA slapped it with an R rating instead of an X was what ruffled more than a few feathers. In a 1974 article for The New York Times, Roy Meacham wrote that by giving The Exorcist an R rating, they were essentially saying that the movie was suitable for children to see, as long as they were accompanied by an adult, but argued that the organization "certainly wasn't thinking about the youngsters and the possibility of traumatic damage to them from the movie's unremitting and violent assault upon the emotions." Meacham relayed an incident about a young girl being "removed from a showing ... and placed in an ambulance."

4. Police in Washington, D.C. threatened to arrest anyone who sold a ticket to The Exorcist to any non-adults.

Meacham's article made specific mention of Washington, D.C. being a prime place where children and teens were interested in seeing The Exorcist—partly because it had been shot in the area and they were excited to see their neighborhoods on the big screen. But local police acted swiftly to ban any underage moviegoers from entering a screening of The Exorcist (regardless of whether they were accompanied by an adult):

"Early in the morning on New Year's Day, Washington became the first city ever to bar children from a film the review board said they could see. After conferring with the U.S. Attorney's Office, officers from the police department's morals division warned the management of the Cinema Theater that arrests would be made if any more tickets were sold for use by minors. A sign was put up at the theater's box office reading, As a result of a ruling by the U.S. District Attorney's Office, no one under the age of 17 will be admitted to The Exorcist.' Advertising for the film now carries a similar warning."

Despite the negative publicity, the MPAA stood behind its R rating. They stated that the movie's lack of nudity or overt sexuality meant it qualified for an R, not X, rating.

5. UK audiences had a hard time finding The Exorcist for many years.

Linda Blair stars in The Exorcist (1973).FilmPublicityArchive/Hulton Archive/United Archives via Getty Images

While The Exorcist was a box office hit when it was released in the UK in 1974, a handful of local religious groups protested the film's release and ended up getting it banned in certain areas. But it faced an even bigger challenge several years after being released on VHS. While the movie was released without issue in 1981, the 1984 Video Recordings Act led to the movie being pulled from shelves in 1988. (Because the film featured a 12-year-old girl there was concern that it would be particularly appealing to kids in that same age demographic). It took more than a decade for the film to be made available to home viewers; in 1999, it was finally re-released.

6. The name of the demon in The Exorcist is Pazuzu.

Though it’s never stated in the film, the demon that takes possession of Regan MacNeil has a name: Pazuzu, which is taken from the name of the king of the demons in Assyrian and Babylonian mythology.

7. Mercedes McCambridge provided the voice of the demon in The Exorcist.

Warner Bros. Home Entertainment

The woman Orson Welles once dubbed “the world’s greatest living radio actress” was hired to provide the voice for Linda Blair’s most demonic moments, a decision that became the source of much controversy when McCambridge was not credited for her performance. Some say that this decision was solely McCambridge’s, who claimed that she didn’t want to take away from Blair’s performance, then later changed her mind. Under the threat of legal action, her name was quickly added to the credits.

8. Chain-smoking and whiskey helped McCambridge achieve Pazuzu's raspiness in The Exorcist.

Sounding like a demon has its downsides. In the case of McCambridge, she believed that chain smoking and a diet of raw eggs and whiskey were the key to a great vocal performance.

9. Pig squeals were a key part of The Exorcist's sound design.

Much of Regan’s moaning and grunting were created by remixing pig squeals. When the demon is finally exorcised from her body, the sound you hear is a group of pigs being led to slaughter.

10. The Exorcist was the first horror film to be nominated for a Best Picture Oscar.

William Friedkin, Max von Sydow, Jason Miller, and Linda Blair on the set of The Exorcist (1973).FilmPublicityArchive/United Archives/Hulton Archive via Getty Images

The horror genre has never gotten much love from the Academy. Though there still seems to be a bias against scary movies during awards season, The Exorcist earned 10 Oscar nominations in 1974, including a Best Supporting Actress nod for Linda Blair, who was just 15 years old at the time. Unfortunately, the teenager’s nomination was met with much controversy as word about McCambridge’s contribution to the role spread.

11. Violet Beauregarde was considered for the role of Regan in The Exorcist.

Denise Nickerson, who most famously played Violet Beauregarde in Mel Stuart’s Willy Wonka & the Chocolate Factory, was in contention for the role of Regan. But then her parents got a hold of the script and, troubled by what they read, pulled her from the production’s shortlist of young actresses.

12. Linda Blair's mother loved The Exorcist script.

Ironically, Linda Blair’s agents never even considered her for the role, though they did send the producers more than two dozen other young actresses to consider. It was Blair’s mother who brought her to the attention of the studio’s casting department and Friedkin.

13. William Peter Blatty insisted that William Friedkin direct The Exorcist.

William Friedkin discusses a scene with Linda Blair during the making of The Exorcist (1973).Alan Band/Keystone/Hulton Archive/Getty Images

Blatty made a smart decision when he sold the rights to his novel, but stayed on as one of The Exorcist’s producers. That way, his opinion would have to matter. And while the studio had its own short list of directors to approach for the gig—Arthur Penn, Peter Bogdanovich, Mike Nichols, and Stanley Kubrick among them—Blatty only had eyes for Friedkin, believing that the film would benefit from a grittier style, similar to what Friedkin had done on The French Connection. When the studio told Blatty that they had hired Mark Rydell for the film, Blatty stood his ground—and won!

14. Marlon Brando was the studio's first choice for Father Merrin in The Exorcist.

It was Friedkin who vetoed this decision, believing that any movie starring Marlon Brando would immediately become a “Brando movie,” which would detract from the story at hand. The role eventually went to Max von Sydow.

15. Max von Sydow was only 44 at the time of shooting The Exorcist.

Max von Sydow on the set of The Exorcist (1973).FilmPublicityArchive/United Archives/Hulton Archive via Getty Images

It took many hours in the chair with makeup artist Dick Smith to age the actor the 30 or so years the role required. Some have even joked that there are scenes in which von Sydow is wearing more makeup than the demonic Regan. Von Sydow’s three-hour daily aging process was achieved with a mix of stipple and liquid latex.

16. Jason Miller was a last-minute—albeit intentional—substitution in The Exorcist.

There were a few big names being bandied about for the role of Father Karras, with Jack Nicholson in the early mix before Blatty settled on Stacy Keach. But then Friedkin happened to see a performance of That Championship Season, which was written by and starred Jason Miller. Friedkin knew they had found their man and, as he recounted in his 2013 memoir, The Friedkin Connection (part of which is excerpted in the 40th edition Blu-ray), they purchased Keach out and in stepped Miller, in his feature acting debut.

17. The Exorcist's most famous image is based on a series of René Magritte paintings.

The Exorcist’s most iconic image—the one that would eventually serve as its poster and movie box art—is of the moment that Father Merrin arrives at the MacNeil residence and, illuminated by a street lamp, looks up at the home. This image was inspired by René Magritte’s Empire of Light paintings.

18. "The Exorcist Steps" are still a popular tourist attraction.

Lee J. Cobb ascends the still-famous steps from The Exorcist (1973).Warner Bros. Home Entertainment

At the end of M Street in Washington, D.C. is where you’ll find one of the film’s location landmarks: a set of stone stairs onto (and down) which Regan “throws” Father Karras from her window. Understandably, they have come to be known as “The Exorcist Steps.” Rumor has it that on the day of filming the scene in which a stuntman rolled down the steps, Georgetown students who lived nearby rented out their rooftops to the tune of $5 per person so that interested onlookers could get a better view.

19. Throwing anyone down The Exorcist stairs from Regan's window would be impossible.

Yes, even for a kid with demonic strength, because, in reality, Regan’s window was located about 40 feet from the top of the stairs. It was a bit of Hollywood magic-making—a.k.a. the addition of a wing built by the production’s set decorators—that made the trajectory of Karras’s untimely tumble seem possible.

20. Many of The Exorcist's cast and crew members believed the set was cursed.

Filming in the U.S. took place in both New York City and Washington, D.C. After a number of eerie incidents on the New York City set, including a studio fire that forced the team to rebuild the sets of the house interiors, Blatty and Friedkin regularly brought in a priest, Father King, to bless the cast, crew, and set when production moved to D.C. By the end of the film’s production, nine people associated with its making had passed away.

21. The Exorcist's Regan preferred Andersen's pea soup.

By now it is well known that the substance Regan projectile vomits onto Father Karras in one of the film’s most famous—and disgusting—scenes is pea soup. But more specifically, it’s Andersen’s pea soup, mixed with a little oatmeal. Campbell’s soup was tried, but the crew apparently didn’t like the effect as much.

22. Jason Miller's disgusted reaction to being covered in said pea soup in The Exorcist is authentic.

Friedkin was known for sometimes using manipulative tactics in order to elicit the most authentic reactions possible from his actors. Miller was told that the substance would hit him in the chest only; whether that was a lie or the equipment misfired is debated. But Miller’s disgusted reaction is absolutely real. Unsurprisingly, the scene only required one take.

23. The Exorcist made a few audience members nauseous, too.

So many, in fact, that some theaters began handing out The Exorcist barf bags with every ticket.

24. Several versions of The Exorcist have been released.

If the only time you've ever seen The Exorcist was during its original theatrical release, watching it today might seem like you're watching a different movie altogether. And in some cases, you might be. As is the case with a handful of other classic films, different cuts of The Exorcist have been released over the years. In 2000, audiences were treated to The Exorcist: The Version You've Never Seen, while The Exorcist: Extended Director's Cut arrived in 2010.

25. The Exorcist is a bona fide franchise.

Stellan Skarsgård and Remy Sweeney in Exorcist: The Beginning (2004).Morgan Creek

Given the success of the original The Exorcist, it was only a matter of time before a sequel appeared. In this case, that happened four years after the original movie's release with 1977's The Exorcist II: The Heretic, which again featured Linda Blair and Max von Sydow. The film, which holds an abysmal 15 percent score on Rotten Tomatoes, is regularly cited on Worst Movie Ever lists. In 1990, The Exorcist III, which is set 15 years after the events of the original film, was released to mixed reviews.

Two attempts at a prequel were also made: Paul Schrader directed Dominion: Prequel To The Exorcist, which was eventually scrapped and retooled by Renny Harlin as 2004's Exorcist: The Beginning. But Schrader's version ended up being released a year later anyway.

26. The Exorcist is about to get a reboot.

In 2018, David Gordon Green and Danny McBride breathed new life into John Carpenter's Halloween franchise with a direct sequel to the original film starring Jamie Lee Curtis (with two more films on the way). On July 26, 2021, it was announced that the duo—along with writers Scott Teems and Peter Sattler—would be teaming up with Blumhouse to create a new The Exorcist trilogy for Peacock. The trilogy will follow the same pattern as the Halloween movies in that the initial film will be a direct sequel to Friedkin's original movie and will bring back original star Ellen Burstyn. Hamilton's Leslie Odom Jr. will also star.

A version of this story ran in 2018; it has been updated for 2021.