Continuity mistake: In the story titled "Quebec Province 1975", child witch Lucy gets back at her bullying cousin Angela by shrinking her to the size of a mouse. Minutes later, Angela looks up, lifts her hands over her head and begs for mercy. Obviously Lucy is preparing to step on her. But we see Lucy lifting her foot off the floor several seconds after Angela starts begging.
Visible crew/equipment: When the Black Knight falls from his horse while attacking Dennis there is a lorry parked in the background. (01:33:05)
Revealing mistake: At one point in the movie, dumptrucks are sent in to contain the Mighty Peking Man. You can tell that these, like most of the movie are toys.
Continuity mistake: When the crew hauls the female orca aboard the boat, the harpoon line is wrapped around her entire body several times. When they cut the rope and drop her into the water, the line is wrapped only around her tail. When the male orca is pushing her at sea, the rope is again wrapped around her entire body.
Visible crew/equipment: During the opening scene when the boat is being pushed ashore you can see the shadow of the boom mike in the water's edge.
Continuity mistake: Henry takes off the wrong shoe/sock to dry off.
Continuity mistake: When Pat is attacked on the stain glassed window near the start, she has blood on her right cheek. When she is then dropped and hung, the blood stains are different. (00:12:20 - 00:13:00)
Continuity mistake: In the opening scenes, when David is chiding Gail for grabbing him through the porthole of the wreck, his right hand is gloved, then ungloved, then regloved..all in the space of a few moments.
Factual error: In the hypnosis scene, when father Marrin is crossing himself, he is doing it the wrong way - from right to left. (00:20:40)
Continuity mistake: The senator is tossed out of the boat and consumed (with the exception of his head) by the monster, and yet the boat is full of blood.
Revealing mistake: The supposed deceased dog is breathing as Rack and spider lady examine him.
Revealing mistake: After Ethel has died and Brenda is crying over her, there is a slight twitch in Ethel's eyes.