Continuity mistake: When Dennis is sitting in his boat talking with Griselda and Mr.Fishfinger he gets covered in rubbish. Although he wipes most of it off there is spaghetti left on his hat and jacket. In the wide shots, though, he is clean. (00:08:20)
Continuity mistake: When Dennis first meets the man who cut his own foot off, it's because he shoved his hand (with a cup in it) right in front of his face. When the shot changes so we can look down at who it was, we see that his hand is nowhere near Dennis' face (he would have had to have been standing up and leaning over to reach his face, when we see him he's sitting down and leaning back against a wall).
Continuity mistake: When the peasant with a rock is trying to get past the two guards into the city in some shots there is a wooden pole between the guards and in other shots there isn't. (00:21:00)
Continuity mistake: In the armoury, when Dennis is trying to improve the efficiency of the riveters, the glove being riveted is only rotated in the close up shots. In the other shots they are hammering the rivets into the same hole every time. (00:46:20)
Continuity mistake: Wat Dabney's severed foot changes position on the sheet in front of him. (00:37:30)
Continuity mistake: When Dennis and Ethel are talking during the hide-and-seek competition, they are sitting next to a table with a flask on it and a sword stuck in the ground next to it. In the closeup, the sword has gone. (01:14:30)
Continuity mistake: As Mr. Fishfinger is being rescued by Dennis, some bits of rope appear on his stomach. (01:25:10)
Continuity mistake: While Dennis is talking with Mr.Fishfinger, a piece of straw stuck in Dennis' hair suddenly vanishes. (00:04:40)
Continuity mistake: The peasant with the rock is killed by the Jabberwock. When his skeleton first lands next the Dennis, it has a bit of flesh left on it but lots of bone is visible. The shot then changes to show Dennis backing away and the peasant's corpse now has a lot more flesh on it and the legs are in a different position. (00:31:15)
Continuity mistake: Just before Dennis rescues the Fishfinger family, the knight is riding the horse that the Dog knight was riding earlier. When the Knight and Dennis are walking through the destroyed village the knight is riding a different horse. The pattern of white on its nose is very different. (01:23:15 - 01:29:35)
