Continuity mistake: In order to tiptoe across the tacks without being hurt, Tom puts a metal gauntlet on his feet. At this point, you can see the floor is completely covered in tacks, but when Jerry and Nibbles are at the same spot a little later on, the tacks have disappeared.
Continuity mistake: When Will Stockdale is at the Purple Grotto, at one point the cup full of liquor is at different levels.
Continuity mistake: When Gaston is not allowed to take Gigi out for tea, Madame Alvarez tells him to sit down. As he is seating himself, he unbuttons his jacket. A moment later, he stands up and unbuttons his jacket again.
Continuity mistake: When King Arthur says "A good idea, fool!", Bugs Bunny stops and you can see that behind him is a wall. In the next shot, Bugs is now in front of King's Arthur's chair, and when he says "Beheaded?" he is back in front of the wall again.
Continuity mistake: When the Bayonet is thrown at Strong, it is thrown with the butt of the rifle facing left, but is caught with the butt facing right. (00:41:00)
Continuity mistake: When Elmer Fuddstone appears from his cave, there is a sign saying "Elmer Fuddstone" which was not in the previous shot.
Continuity mistake: When Jeannie is on the settee talking on the telephone, the cord is missing in some shots.