Trivia

The studio originally wanted Benedict Cumberbatch to voice the Grinch using his natural voice, but Benedict felt that, since the rest of the cast is American, the Grinch should have an American accent.

When Cindy-Lou Who and her friend go up into the tree house, the baseball bat on which they ride as a platform has the name "Theodor" carved on it. Theodor Seuss Geisel, a.k.a. Dr. Seuss, wrote the Grinch book.

Max is still the Grinch's morality pet, but instead of being a frightened, timid dog who reluctantly does the Grinch's bidding, Max is very much loving and loyal to the Grinch. While he is by no means a nicer guy, this version of the Grinch is shown to be marginally kinder to Max than in How the Grinch Stole Christmas! (1966) or How the Grinch Stole Christmas (2000), generally by treating him more like a typical dog owner would, and at one point playing with Max with a small, affectionate smile on his face. Overall, the Grinch is much less antisocial than his previous incarnations and it's implied his motive for stealing Christmas is partially more of a Freudian Excuse than out of sheer malice.

This movie was originally scheduled for a November 2017 release, but was moved to November 2018. This was presumably to avoid competition with Sony Animation's The Star (2017), another animated Christmas-related movie. Had this movie been released in 2017, it would've been released sixty years after the Dr. Seuss book on which this movie was based, first published in 1957.

There's a scene where Donna Who is late for her bus and chases after it yelling the bus driver's name "Sam!", who then stops and lets her on. This is a based on a scene in Speed (1994) where Annie does the same thing.

In all of the other versions, the Grinch could not find a reindeer to help him with his heist, so he used Max instead. But in this adaptation, he successfully finds a reindeer and lets it stay at his house with Max.

When asked what is a holiday tradition or Christmas thing that makes him feel most like a Grinch, Benedict Cumberbatch stated: "Excess packaging, It's enough already. We're living (through) environmental disaster after environmental disaster. I don't get why it's not something that's actually fine-able now, to wrap toys and goods in plastic that's not needed. Toys are made of plastic as well. It's plastic on plastic. That is the thing that gets me Grinchy. Everything else is just part of the season. Last minute Christmas shopping? Often you've only got yourself to blame. But I just can't stand all the excess that goes with consumer goods and packaging."

Brad Dourif was replaced by Pharrell Williams as The Narrator.

Benedict Cumberbatch compared the Grinch to his motion-capture performance of Smaug in The Hobbit trilogy: "for this character, a little bit like Smaug, he lives in a mountain and he's quite angry and isolated and alone, so apart from talking to Max who doesn't verbalize, it helped for the character in this instance. It does get very weird if you're doing quick-fire dialogue and you're not in the room with the people you're acting with."

In How the Grinch Stole Christmas! (1966) and How the Grinch Stole Christmas (2000), the Grinch gets the idea of disguising himself as Santa Claus when he sees Max's face being covered with snow that vaguely resembles Santa's face. In the book and this version, the Grinch comes up with the idea of disguising himself as Santa completely on his own.

Martha May Whover from How the Grinch Stole Christmas (2000) was completely written off from this version, as the writers felt that a voluptuous love interest is not the kind of message they wanted to acquire this time, which is connected to the controversy from The Cat in the Hat (2003). Like many other versions of the classic Christmas story, the Grinch was never given a love interest.

This movie marks the second time an English actor has voiced the character of the Grinch. The first was with Boris Karloff in How the Grinch Stole Christmas! (1966).

When asked how prepping and going into record compared to motion capture, Benedict Cumberbatch stated: "it's far less mobile. It's a fixed point, you have to create a lot of energy, but it's around a really fixed access of microphone, whether you're being hauled around in a sleigh round a mountain or flung through a catapult or talking very quietly to your dog - all those levels have to come around a microphone. Your voice has to be supported by the action that makes it sound that way, but you have to stay on the mic, whereas with motion capture you can really swing yourself about because you have a headset usually; you can throw your body around the landscape, except you're in isolation at the mic without (Dame) Angela Lansbury or Kenan Thompson or any of the thousand people I did talk to."

Dame Angela Lansbury's third theatrically released animated movie. The others being Beauty and the Beast (1991) and Anastasia (1997).

The Grinch in How the Grinch Stole Christmas! (1966) and How the Grinch Stole Christmas (2000) wore a Santa Claus costume, but makes no further attempt to really look like Santa. In this movie, the Grinch plays a more convincing looking Santa including a beard and boots.

Since the Grinch has a very distinctive shape and look, the animators took inspiration from the book, Benedict Cumberbatch stated: "for certain performative strokes definitely, they film your performance while you're doing it, so it's not in isolation from that, they've managed to embody this voice in a character that's utterly unique, and I don't think looks too much like me, they record every session so they can see the performances as well as hear (it), but it's not like facial capture, I never did anything of that nature."

This was Benedict Cumberbatch's second animated movie. The first being Penguins of Madagascar (2014).

Released a month before Mowgli: Legend of the Jungle (2018) also starring Benedict Cumberbatch voicing the main antagonist, Shere Khan.

The movie's animation was made using Autodesk Maya.

Illumination's second movie to have a narrator, after Minions (2015).

The first official footage of this movie was released by Illumination Entertainment as a television spot on February 9, 2018, to capitalize on the 2018 Winter Olympics in Pyeongchang, South Korea.

The Grinch's intellect to build inventions originally came from The Grinch Grinches the Cat in the Hat (1982). This trait was repeated in How the Grinch Stole Christmas (2000) and the animated film.

This is the second Grinch adaptation released by Universal Pictures. The first being How the Grinch Stole Christmas (2000).

In 2018, Producer Scott Mosier took over from Peter Candeland as director.

This movie marks the second time that The Grinch is shown as a child. The first being How the Grinch Stole Christmas (2000).

The second Illumination movie with a dog named Max, first was The Secret Life of Pets (2016).

Pharrell Williams, who is the narrator of this movie, and Tyler the Creator, who provided songs for the soundtrack, collaborated on the song, "The Mantra", which is on the Creed II (2018) soundtrack.

This is Illumination's first PG-rated animated movie for thematic elements.

Illumination Entertainment's second movie to feature no humans after Sing (2016), and the second animated Dr. Seuss movie to feature the furry humanoids seen commonly in Dr. Seuss books, after Horton Hears a Who! (2008).

In the Latin American Spanish dub, the Grinch was voiced by Eugenio Derbez; in the Japanese dub, the Grinch was voiced by Yô Ôizumi, better known to video game fans as the Japanese voice of Professor Layton, and also playing Kureo Mado in Tokyo Ghoul (2017). In the Brazilian Portuguese dub, the Grinch was voiced by Lázaro Ramos.

The second theatrical Dr. Seuss animated movie rated PG by the M.P.A.A., after The Lorax (2012), and the fourth theatrical Dr. Seuss movie rated PG.

In the Spain Spanish dub, the Grinch was voiced by Ernesto Alterio.

The eighth Universal Pictures animated movie rated PG, of which all previous animated Universal Pictures movies released after The Tale of Despereaux (2008) (Universal Pictures' only CGI movie Rated G) were rated as such.

This is the first Illumination movie to not feature a main antagonist.

In the Latin American Spanish dub: Rubén Cerda, who voiced the Grinch's singing voice in How the Grinch Stole Christmas (2000), reprised the character in this dub, through the acting voice was voiced by Eugenio Derbez instead, rather than Mario Castañeda.

The Grinch's backstory differs from How the Grinch Stole Christmas (2000), in which the Grinch was publicly humiliated in elementary school as a child due to having to shave at his age.

The third fully CGI animated film based on a Dr. Seuss book, the first being Horton Hears a Who! (2008) and the second being The Lorax (2012).

Rashida Jones' second animated movie, after Inside Out (2015), which came out the same year as Hotel Transylvania 2 (2015). This movie came out the same year as Hotel Transylvania 3: Summer Vacation (2018).

Cindy-Lou Who's nightgown that she wore when the Grinch steals a Christmas tree resembled the dresses worn by the female Smurfs in Smurfs: The Lost Village (2017).

Pharrell Williams did the soundtrack for The Lion King (2019) which was directed by Jon Favreau, who is part of the Marvel Cinematic Universe, of which Benedict Cumberbatch is a part, as Doctor Stephen Strange.

This is the first Universal's computer-animated film to be released in November.

Released two weeks before Black Friday.

The fifth Universal's animated film to be released in November, after An American Tail (1986), The Land Before Time (1988), An American Tail: Fievel Goes West (1991) and We're Back! A Dinosaur's Story (1993).

Pentatonix: singing "God Rest Ye Merry Gentlemen" when the choir was chasing the Grinch with Christmas carols.

Near the end of this movie, the Grinch wears a red and white tie when he's invited over to Cindy-Lou's house for Christmas dinner, a reference to The Cat in the Hat (another Dr. Seuss character) who has the same color pattern hat.

There is a new reason for why the Grinch has to go down to Whoville during the Christmas season. He initially had stockpiles of food to last him until the start of January, but due to his excessive "emotional" eating, he was reduced to a mere bean on a plate just five days shy of Christmas.

This movie differs from its source material - and previous adaptations - in many different ways, especially in the third act. Firstly, in the book and How the Grinch Stole Christmas (2000), the Grinch and Cindy-Lou's Christmas Eve encounter happens because the latter wakes up to get a drink of water and crosses paths with the former. Here, it's because the Grinch gets caught in the trap Cindy-Lou set out for Santa. Secondly, in How the Grinch Stole Christmas! (1966) and the 2000 film, the Grinch is able to save the sleigh by finding "the strength of ten Grinches plus two'". In this movie, he and the sleigh are rescued by Max, Fred, and his reindeer family. Finally, in all previous versions of the story, the Grinch immediately joins the Whos in their Christmas celebration after returning their presents. In this movie, he goes back to Mount Crumpit after returning the presents and apologizing. He doesn't join the Whos until Cindy-Lou invites him to Christmas dinner at her house.