Continuity mistake: After Tamara comes out of the the shower she is completely dry. (00:36:00)
Continuity mistake: As the priest descends down the rope ladder into the church for the first time he is handed a lantern by his friend. In the next shot the camera is looking down and you can see that the friend is holding the lantern. Then the next person goes down the same rope ladder and the friend is not holding the lantern, where did the lantern go?
Continuity mistake: The male lead is seen reading an article in the newspaper, the headline of which says "serial killer arrested at Pendleton University," but when he reads the headline aloud, he mentions the professor that killed students at Alpine University, which doesn't match the headline from the paper he's reading.
Continuity mistake: When the shark is brought up to put the needle in his head, it bites off Jim's arm, leaving only a bit left there, but when they are wheeling him to the helicopter you see that he's got more arm than before. (00:33:50 - 00:35:25)
Continuity mistake: When Seymour tries to kill the plant he pulls a gun, the gun is a six shooter, the plant grabs the gun and fires at the guy, then he fires some more, in total the plant fires 9 shots with a six shooter...
Continuity mistake: In the scene where Jessica is in the shower crying and the power goes out, she gets out, puts on a white t-shirt and goes walking around the house. When she walks through the garage door and grabs a hammer, there is blood on the front of the t-shirt (right at or a little lower than her waist and looks like someone grabbed the shirt with a bloody hand). Where did it come from? She didn't run into anything or anyone. [There's a deleted scene showing her step on a piece of glass. She gets blood on her hands when she pulls the glass out, then presumably wipes her hands on her shirt. Still a mistake, as removing that scene means the blood appears from nowhere, but there's the reason.]
Continuity mistake: In the first successful teleportation of the baboon, there is one scene where Brundle's hands move from being straight to folded in just one shot.