Continuity mistake: When Don Knotts is in the old Simmons mansion, he falls down a chute of some kind. If you watch closely you will see the stunt person looks nothing like Don Knotts. It is a younger man with very straight hair.
Continuity mistake: When the Batmobile is going to park (before the bomb scene) there is a sign saying "Mobey Dick Parking Only". When he is later carrying the bomb and passes by the Batmobile the sign is not there.
Continuity mistake: At the end when the sled full of Christmas stuff is on the mountaintop, it starts sliding off the edge. It's going fast enough that it should be long gone by the time the Grinch reaches it, but when he does it's still right near the top of the mountain.
Continuity mistake: When Charlie Brown holds the door for Snoopy before the gang leaves to trick or treat, his costume doesn't have all the extra holes in it like it does in the scenes before and after.
Continuity mistake: Throughout the movie Elsa wears a collar. In the scene where she runs away the collar is visibly in place - a few minutes later, when she's found with the elephant, the collar has disappeared.
Continuity mistake: Brutus, the Great Dane, is shown crawling from right to left on the ground near the edge of the planter. After a brief close-up of Mark, his owner, Brutus is shown crawling from right to left in the exact same spot again. (01:16:10)
Continuity mistake: When the four kids uncouple the coach from the engine Carole is wearing trousers. The stationmaster tells them to stand clear as the engine pulls away, in the first shot of the children after the engine has gone Carole is still wearing her trousers but in the second shot Carole is now wearing a skirt.
Continuity mistake: The huge gash in the left rear tire of the Dragula Herman repairs with his scarf and piece of tape disappears the rest of the race.