Write What You Know: Those who knew Dr. Seuss personally cite The Grinch as his most autobiographical character. In addition to being something of a recluse himself, Seuss's home and studio were on a hill overlooking Los Angeles, and ever Christmas, he'd scoff at the chintzy lights and decorations adorning all of the houses. He was 53 years old when he wrote the book, hence The Grinch's line about putting up with Christmas "for 53 years."
Originally run on CBS for over 30 years, ABC got the special during the Turn of the Millennium and would often run it in double-features with the 2000 film. In 2015 the rights went to NBC, making it possibly the first Christmas special to have been on all of the original Big Three networks at some point or other. It has also aired on both The WB and The CW, and on cable it has aired on Cartoon Network, Boomerang, WGN America, TNT, and TBS.
Distribution-wise, the special originally belonged to MGM Television, but was a part of the library Ted Turner purchased along with MGM in 1986 (having only kept MGM itself for 74 days, but kept the library afterwards). As a result, it fell under Turner's in-house distribution firm until 1996, when the Tuner-Time Warner merger occurred and Turner Entertainment was absorbed into Warner Bros., who have since held the rights; since 1986, TBS, TNT and later Cartoon Network have broadcast the special on cable.
Disowned Adaptation: Dr. Seuss himself did not like the end result of the cartoon much, citing it as having too much of Chuck Jones' own art style. He much preferred the later Grinch (and other Seuss-inspired) specials that were created by Friz Freleng.
Edited for Syndication: For many years US network broadcasts deleted one of the "You're a Mean One" verses ("You're a rotter, Mr. Grinch...") as well as a genuinely disturbing moment in which the Grinch does his Slasher Smile while leering at several young Whos in their bed. Later ABC broadcasts, and 2015 and 2017-onward NBC airings, cut the special down to the bare minimum to make room for more ads, keeping the important story parts, deleting many of the visual gags, as well as a shot of the Grinch cracking his whip while Max pulls the sleigh up Mt. Crumpet. Averted with broadcasts on the Turner networks such as TBS and Cartoon Network, which show the special uncut, probably due to being cable networks that can make revenue off cable subscriptions in addition to ads (plus owning the special helps); in return, though, TBS speeds up the special slightly to squeeze more commercials in. NBC also restored The Grinch to its original runtime in 2016, in honor of its 50th anniversary, but then started editing it in 2019 (cutting some verses from "You're a Mean One") to make room for showing How to Train Your Dragon: Homecoming uncut.
The original 1966 broadcast of the special was sponsored by The Foundation for Full Service Banks and contained sponsor plugs at the beginning and end of the special. However, just like the Coca Cola plugs from A Charlie Brown Christmas they were removed after the first airing (due to the specials message contradicting the sponsors services) and are notoriously difficult to find nowadays.
According to Chuck Jones' daughter Linda, the original idea was to have Boris Karloff narrate, voice the Grinch, and perform the song "You're a Mean One, Mr. Grinch", that is until Karloff informed Jones he can't actually sing, thus paving the way for Thurl Ravenscroft. Stage productions, and the live-action film would keep the idea of the Grinch's actor singing it though.
Adored by the Network: And how. Freeform (as ABC Family) loved playing this movie during the 25 Days of Christmas event. For 2016, the cable rights were reclaimed by HBO, but their Grinch obsession came back when they got the rights back the following year.
Inverted with the older Grinch, who is played by the 38-year-old Jim Carrey despite the character being over 50 years old.
Played straight with the 8-year-old Grinch, who was played by Josh Ryan Evans (born in 1982).
In the Latin American Spanish dub, Mario Castañeda was also the same age as Carrey when the former dubbed the Grinch. Meanwhile, the eight-year-old Grinch was dubbed by the 21-year-old Luis Daniel Ramírez
Dyeing for Your Art: Jim Carrey found the mask to be horrifyingly claustrophobic and the yak hair used in the suit was constantly itching his skin. It got to the point where an interrogation expert who specialized in training special forces to endure torture had to be brought in to help Carrey cope. The expert's suggestion was for Carrey to distract himself from the discomfort was to smoke constantly, to eat everything in sight, and occasionally punch himself in the thigh to give him something else to focus on, which Carrey did throughout production. Carrey also said that during the makeup process he would concentrate on spinning a smooth stone in his wrong hand.
Executive Meddling: According to Ron Howard, most of the raunchier jokes in the movie were forced in by the studio.
Fake American: The Canadian-born Jim Carrey affects an American accent as the Grinch.
In Memoriam: The film ends with white text on a black background, reading: Dedicated to Jean Speegle Howard "who loved Christmas the most." Jean died in September 2000 due to heart and respiratory illness.
Tim Burton was offered a chance to direct the Live-Action Adaptation, but could not due to a conflict with another project (presumed to be what would become, many years later and without his involvement, Goosebumps) he was working on at the time.
The Grinch was originally going to have white fur like in the book, but Ron Howard also wanted it to be an adaptation of the 1966 cartoon.