Continuity mistake: After the Grinch unscrews the light bulb in the town Christmas tree, all the lights in the town go dark and the Grinch starts to take off in his sled-thing. When they show a close up of him, the lights are on. Then a few seconds later, the lights are off again.
Continuity mistake: After the Grinch stole all of the presents, Officer Wholihan gets into his police car and drags the mayor's bed out of his house. When the bed smashes through the window it breaks the top off the middle post of the bed. Then when it comes back to the shot of the bed it's been fixed.
Continuity mistake: When the Grinch is messing up the mail in the back room, he takes out a package and puts it in another one. When he takes his hand out the package falls out and lands next to the pile of presents. The mistake is when the camera goes to another shot, the package is not lying on the ground as it was before.
Continuity mistake: When Miss Martha May is shooting the lights onto her house you see them lit as they are being fed into and coming out of the machine when the camera is pointing on her but when it's a far off shoot only the lights coming out are lit not the ones on the feeding wheel.
Continuity mistake: When the Grinch burns the Christmas tree, in an overhead shot he isn't anywhere in sight, then in the following closeup he's back beside the ashes of the tree.
Continuity mistake: When Betty Lou watches Martha May shoot the lights from her machine, she is holding a string of lit Christmas lights. Then in the first shot when she leans over the roof, holding the Christmas lights, the strings of lights is off and are then lit in the following shots.
Continuity mistake: In the post office scene, when Cindy is talking to her dad, you can see a post box marked "Grinch" and it has nothing in it. Later we are shown a close-up of the Grinch mailbox and it has spider webs in it.
Continuity mistake: As the Grinch and Max stand by the 'Dumpit to Crumpit' pipe, Max is missing his collar. It's back on him after they arrive at the dump.
Continuity mistake: When the two women who adopted the Grinch show him a plate of cookies on a santa plate when he was younger, one cookie with red icing on it falls off the plate. In the next shot it's back on again.
Continuity mistake: When Max bites the Grinch in the mail room, and the Grinch starts spinning around, a pile of presents appears under the wall of mail slots between shots.
Continuity mistake: When the little girl first sees the Grinch the orange light is spinning around and you can hear a siren. Then when the Grinch speaks it conveniently turns off and back on again when he finishes.
Continuity mistake: In the wide shot of the town square after the mayor says there "is no Grinch problem here!", the yellow car that had a full cab that the red car hit is missing, and the red car's right headlight that was knocked out in the crash with the yellow car is back in place.
Continuity mistake: In the scene where the Grinch is talking to the town after he flips out during the Whobilation,the mayor in the background switches from facing inward to his assistant to facing outwards.
Continuity mistake: In the wide shot that would be a view from the roof of Betty Lou's house, you can see the spool of lights on Martha May's cannon isn't lit up or moving.
Continuity mistake: When Lou enters the classroom, the teacher's yardstick switches position from straight up and down to flat as the shot perspectives change.
Continuity mistake: After the Grinch answers the cop's greeting with "Flatfoot!", two Whos carrying packages pass by him, and he watches them pass. As the Grinch approaches two Who children to give them the hacksaw, the same package-laden Whos pass by again.
Continuity mistake: The Grinch holds the electric razor in his palm, then grasps it finger by finger. The next instant cut shot of him shows him holding the razor, but his hand is open.
Continuity mistake: As Cindy Lou sinks in the sorter, her legs go from sticking up from the knees to only her feet visible in a second.
Continuity mistake: When he's talking to Cindy Lou in the Post Office, Lou is riding on the movable ladder, When he says "You kids and the Grinch", he's right at the end of the track when the camera cuts to Cindy Lou. When it cuts back, he's just stopping at the end. The sound while the camera is on Cindy Lou suggested that the track was longer than it was.
Continuity mistake: When the Grinch goes to wrap Cindy, he grabs the end of the wrap with his right hand and pulls. Suddenly, he has both hands on it, and there was the sound of his left hand grabbing added in.
Answer: It was a rocket sleigh.