Other mistake: When Lizard enters the trailer he closes the trailer door. When Lynn runs towards the trailer and enters it the door was already open.
Revealing mistake: When the dad goes back to the gas station and finds the attendant in the outhouse, when he shoots himself his head blows a split second before the gun is actually fired.
Continuity mistake: When Brenda saturates the tire with lighter fluid, right before she lights it, it turns to burn gel.
Continuity mistake: At the very end of the movie, when Doug returns with the dog and the baby, the survivors have a big hug. Then the camera pans out and we discover someone is watching them. When the camera pans out there is absolutely no sign of the trailer that just blew up or the car.
Continuity mistake: At the beginning when Big Bob and his family are first shown, at the gas station, their suburban has BF Goodrich all terrain tires mounted on chrome wagon wheel rims, after that first shot the tires and wheels change to Bridgestone Duelers on silver bullet hole wheels.
Continuity mistake: When Doug goes to rescue his baby daughter from the kidnapper's bed, he creeps past the living room to see a bald matron watching TV and combing a wig. Then after he grabs his baby, and creeps past the living room, the bald matron is still sitting and combing the wig. But 5-seconds later, when he gets a few feet down the same hallway, that matron suddenly appears out of nowhere and attacks him.
Continuity mistake: In the shot where Doug's fingers are cut off, the severed finger that remains on the floor is covered in blood, but next shot of him pulling his hand away shows almost no blood on the severed finger.
Continuity mistake: The scene where the father has gone back to the gas station to look for help, he purchases a bottle of water and pays for it. He takes a sip and walks into the back. He puts the bottle down on the table, and the bottle is now half empty.
Continuity mistake: In the scene where Doug is standing by the generator and finds his baby, he hides from Cyst against the house's wall as Cyst passes, dragging a corpse. After Cyst passes, Beast whines which makes Cyst turn. In that split-second, Doug and Beast manage to get inside the rusty car a couple of feet away.
Continuity mistake: Bobby's boxer shorts go from blue in the beginning of the movie to black towards the end.
Answer: Pluto puts his hand over Brenda's mouth and Ethel doesn't bother to look over.