Jim Carrey spent 92 days in the Grinch make-up with 2.5 hours in the morning getting in, and 1 hour in the evening to get out. According to the actor, he became a “zen master” while sitting in the make-up chair.
One morning, director Ron Howard came in at 3:30 to put on the Grinch suit with full make-up and directed the entire day with the suit on. Carrey said that when he first saw Howard in full Grinch outfit, he was angered, mistaking the director for a stunt double who looked nothing like him.
Carrey accepted the role of The Grinch when he heard a tape of a kid’s choir singing the song “You’re A Mean One Mr. Grinch”. Eddie Murphy and Jack Nicholson were also considered to play The Grinch. – IMDB
The lyrics for “You’re A Mean One Mr. Grinch” were written by Theodor “Dr. Seuss” Geisel, the music was composed by Albert Hague, and the song was performed by Thurl Ravenscroft, best known as the voice of Tony the Tiger and one of the voices from The Haunted Mansion in Disneyland. Because Ravenscroft was not credited in the closing credits of the special, it is often mistakenly attributed to Boris Karloff, who served as narrator and the voice of the Grinch in the special but who himself could not sing. – Wikipedia
Anthony Hopkins served as the voice of the narrator in the live action version of How The Grinch Stole Christmas, and Jim Carrey himself does all the singing (and voices) for “You’re A Mean One Mr. Grinch”.