The Whoville set was built mostly on the backlot of Universal Studios behind the still-standing Bates Motel. During a break in filming Jim Carrey surprised and scared tourists on the Universal Backlot Tour by running out of the hotel wearing a dress and brandishing a knife. Nobody recognized him, and the tour guide at Universal Studios will tell you the story when you pass by the hotel on the Backlot Tour.

No movie has featured so many characters in heavy makeup since The Wizard of Oz.

The line “6:30 p.m. “Dinner with me” I can’t cancel that again.” was improvised by Jim Carrey.

The scene where The Grinch is directing his dog, Max, before stealing Christmas, is Jim Carrey doing a parody of director Ron Howard.

The original Grinch was not green, he was black and white with some red and pink splotches.

Jim Carrey’s yellow contact lenses proved to be so uncomfortable that he was unable to wear them at times during filming. This required that some shots of his eyes be colored in post-production.

The prosthetic make-up Jim Carrey wore took three hours to apply. Carrey felt so horribly confined and uncomfortable in the latex skin he needed counseling from a Navy SEAL who taught him torture-resistance techniques.

One morning, director Ron Howard put on the Grinch suit with full make-up and directed the entire day with the suit on. Jim Carrey said that when he first saw him in full Grinch outfit, he was angered, mistaking the director for a stunt double who looked nothing like him.

Audrey Geisel came to the set of Man on the Moon to see if Jim Carrey was right to play the Grinch. He was so deep into the character of Andy Kaufman, however he had to essentially do an impression of himself doing an impression of The Grinch, and that was what got him the gig.

For a while, Tim Burton was considering to direct, but could not due to a conflict with another movie