Continuity mistake: When Elvis hands a pair of binoculars to his pappy, you can see there is a swarm of flies buzzing around Pappy, but in the next shot the flies have disappeared.
Factual error: Karnak was an Egyptian city, not one of their gods.
Continuity mistake: When Bugs is sleeping in his cot, he has nothing around his neck. But when he cries for a glass of water, a bow-tie appears.
Continuity mistake: The car is out of gas, and Sylva Koscina gets impatient. As the shot changes, Walter Chiari's arm is on top of the car door (it wasn't in the first shot) and Dorian Gray crosses again her arms on top of the bag - assuming the same pose she already had. (00:17:00)
Other mistake: A police officer fires two shots, hitting a bank robber in the back. The "bullets" do not make holes in the robber's coat. All they do is create two tiny puffs of dust.
Continuity mistake: Christopher Lee looks outside his useless nephew's room and spots two hot Swedish girls. Renato Rascel has a bottle of wine in hand and walks towards him, but the bottle is gone when he tries to stop him. (00:23:40)
Continuity mistake: Mrs. Carrie Lane puts some respect in the rough cowboys with her rifle. As Boone moves towards her and asks for Ben Brigade for some moral support, the horse Billy John is on moves away from the other horse quite a bit. The horse is back in line at the cut. The natural light also changed. (00:11:05)
Continuity mistake: When Richard Hannay jumps from the Sheriff's window into a passing truck it is full of bales of hay. The next time we see him in the truck it is full of sheep and the bales of hay have vanished.
Continuity mistake: When Witch Hazel is chasing Bugs Bunny up the castle tower, Bugs throws a stone through the window before Hazel appears from behind the curtains. When we see Bugs dressed up as Romeo, the glass panes have disappeared, and when we see Hazel dressed up as Juliet, they are back again.
Other mistake: After the intro, one girl in the bar peeks from the window and goes; "Say, here comes Gordy and Jennie." And indeed the duo is getting off the car and joins them. The problem is, the window is on the opposite side of the entrance and there's diegetic music playing throughout the scene. In other words, she saw them parking to the left, but in a split second they are coming through a door on the right. (00:02:40)