Revealing mistake: In the hut in the swamps Zack lights a candle. The resulting light is obviously from a spotlight because the flame and the shadows are perfectly still. (01:09:30)
Revealing mistake: When Sean Connery and the others are examining the corpse found in the water, the dead body's eyes blink. (01:01:05)
Revealing mistake: When Papet peers through a telescope, it's obvious that the lens cap is on.
Revealing mistake: When Danny DeVito brings home the 'bigger dog' he says for the new dog to go eat the little dog that always bothers him. He lets the dog go and the dog goes after the little one. But when they show the dog chasing the little one he almost runs right past him. There must have been a trainer on the other side of the set calling the dogs to come over because he wasn't chasing the little dog. (00:40:30)
Revealing mistake: When Arnold throws the bad guy through the glass door at the dress shop, it shatters a split second prior to him going through it. (00:55:40)
Revealing mistake: At the end of the movie, the main creature has the head of a human. However, in a number of shots you can see the actor's neck showing how they made the head "appear" to be attached to this creature.
Revealing mistake: The laser blasts the robots fire instantly exterminate or destroy most everything in their path. However, when the guys are shooting at them during the mall blast-out, the lasers suddenly don't do much damage at all.
Revealing mistake: As Sgt. Highway turns the dead body with a cigar in the pocket you can see its right arm move to avoid twisting. (01:38:05)
Revealing mistake: When Howard's running from the female bikers, Satan's Sluts, look closely at one and you can tell it's a guy in drag, one wearing a dark blond wig. (00:10:00)
Suggested correction: I was in this part of the movie, everyone in this scene (except for the duck) is female.
Revealing mistake: At the dinner at the Indian restaurant, when Howie Mandel begins eating the flowers, Blake Edwards' daughter breaks character and cracks a smile, regaining the deadpan composure of the role only at the very end and in the next shot. (00:57:25)
Revealing mistake: During the credits, Don Falcone is reading about the bloody feud between fellow cheesemaking mafia families Lombardi and Zanetti. The first article he browses is the April 7, 1985 edition of the Italian newspaper "Il Messaggero," with a bad glue-on job (the left column's font does not match the rest of the actual newspaper). He then reads about the car bombs in another newspaper, "Paese Sera." Here the prop design is better, but if you can read Italian, you can easily see that the article does not match its headline at all; it's not about a brutal mafia murder, but rather about the "sliding wage scale" referendum which was taking place in the country at the time the movie was shot, in 1985. (00:03:00 - 00:04:15)
Revealing mistake: Vanity's stunt double is obvious as she drives the Corvette under the semi truck's trailer.
Revealing mistake: At the end when Katrina's skeleton flips off Keith, you can plainly see a crew member's hand moving the arm.
Revealing mistake: As the bad guys' Ford pickup flips end over end, the device making it flip is briefly visible. Also, the "bad guys" still in the truck turn out to be dummies.
Revealing mistake: When the crocodile attacks Sue from the water, it holds on to her canteen for two shots. You can see that the animal actually holds on to a prepared version of the canteen - it is cut in half, with its lower teeth inside to hold it more "comfortably" during the pull.
Revealing mistake: When Norman drives Dukes car into the pond, it's obvious no one is in it.
Revealing mistake: When the bully's held up by Sam wires can be faintly seen.
Revealing mistake: In the Director's Cut ending when Audrey II eats Seymour, it spits out his glasses, and they land in front of the camera. They pulled this off by having a pair of glasses inside the plant's mouth that would be yanked out by a string, and another pair of glasses would be dropped in front of the camera. However, the first pair gets caught in the teeth and fall back inside the mouth, but the other pair lands on the ground anyway.
Revealing mistake: Obvious stunt man for Carrie Snodgrass due to having brown hair while she's a dark blonde when hanging from an axe handle near the end of the movie. (01:35:09)
Revealing mistake: The chairman parks his car in front of Bel Fuse Ltd. And goes upstairs. His car explodes, but does it in front of a different building, probably switching to a stage building front; the metal doors don't have vents anymore and there are visible join lines in the asphalt and the cement. (00:15:10 - 00:15:40)