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.
Revealing mistake: When the Grinch is cutting Max's antler, the cut lines appear on the prongs before he actually starts to cut.
Other mistake: When the Grinch is cutting Max's antler, the pieces that have fallen on the floor suddenly jump several inches closer to Max.
Continuity mistake: When the Grinch puts the antler on Max's head it has five prongs. But when Max tips forward, one of the prongs disappears as it's hidden behind his body. The Grinch only cuts off four prongs, but when Max goes upright again, the fifth prong is still gone.
Continuity mistake: When the Grinch has his change of heart, his eyes change from red to blue. However, when he looks up and sees that the sled is about to fall, his eyes are red again. When he's running uphill, they're back to blue.
Suggested correction: His eyes turned red again because he was afraid that the sleigh would fall. After he finds the strength to pull the sleigh back up, his eyes turn blue again.
While it's true his eyes go back to red when he sees the sleigh about to fall, when he's running after it, they're back to blue. They switch back and forth. And you can tell they're suppose to be blue because the part around it is white (the sclera if you will) instead of yellow.
I still think it's a creative choice showing his determination. When he sees the sleigh about to fall, his eyes turn red, they turn blue again when grabs Max, turn red again when the rope holding Max breaks, turn back to blue as he races after it, turn back to red when he realises it's too heavy, and finally go back to blue and stay that way when he finds the strength to pull it up. It's pretty consistent with his emotions in each shot. His eyes are only red during the parts where he isn't determined (and during the parts earlier when he's evil).
Continuity mistake: When the Grinch goes into the first house, you can see the Christmas tree in the background and it has a silver star on top. But later when he steals the star, it's gold.
Revealing mistake: When the Grinch hits the Christmas decoration with the cue stick, the ball rolls over the Christmas tree, not under.
Continuity mistake: Max's antler changes constantly after being cut. The number of cut branches, the size, and locations all changes at various times. At first, it's 4 cut branches. Then when he jumps on the sleigh it's 3, and when he's hooked up to the sleigh, it's just 2.
