Continuity mistake: The first time Carly Beth takes off the mask, it falls to the floor, but suddenly jumps back up to her hands when she tosses to Noah.
The Girl Who Cried Monster - S1-E4
Other mistake: When we see Mr. Mortman transforming the second time, the shot is exactly the same as the first shot that was shown when he first transformed.
Welcome To Camp Nightmare (2) - S1-E6
Other mistake: At the end of the episode, Billy's parents tell him that they are taking him to a dangerous place called Earth and then direct his attention towards the sky where Earth is visible in high detail in broad daylight of the atmosphere of whatever planet they are on. If Earth is visible in such great detail, and at daytime no less, then there is no way Billy could not have already been familiar with it.
Suggested correction: The character is aware that the earth is in the sky, just not that he was being trained for a mission.
There's a difference between noticing an object in the sky and not being familiar with a prominent object in the sky. The show is implying that Billy knows nothing about Earth when his parents point it out to him and tell him it's "a place called Earth." This would be like someone on Earth seeing the Moon almost every night of their life and then not knowing any basic thing about it, including its name, until they were a teenager.
Night Of The Living Dummy II - S1-E10
Visible crew/equipment: In a wide shot of Slappy about to smash the guitar on the parents you can see that he is propped up on a stand.
Night Of The Living Dummy II - S1-E10
Continuity mistake: After Slappy's head is smashed off, the position of the broken face on the floor changes.
Night Of The Living Dummy II - S1-E10
Continuity mistake: When Amy's parents are talking to her while she eats breakfast, the whipped cream can sitting on the table moves between shots.
Continuity mistake: When Joey and Mickey are walking down the street and Greg and Bird see them, Bird says Mickey's last name as "Knotts" when addressing him. However, in the credit sequence, Mickey's name has been changed to "Ward".
Attack Of The Mutant (1) - S2-E2
Other mistake: In part 2, it was revealed that Libby was really the Masked Mutant all along but, in one scene in this episode, Libby is sitting next to Skipper while the Masked Mutant is standing on top of the bus.
Attack Of The Mutant (1) - S2-E2
Plot hole: Skipper spots the Masked Mutant's headquarters the first time he goes past. He then goes back the next day, and the headquarters have vanished. He then goes back a third time, and the headquarters aren't there yet again. However Skipper says "How can it be. It was right here yesterday," although it wasn't.
Attack Of The Mutant (1) - S2-E2
Continuity mistake: When Skipper and Libby are in the elevator, before it crashes to the floor, Libby backs up right against the wall. In the next shot as the elevator doors open, she is standing in the centre of the elevator.
Attack Of The Mutant (2) - S2-E3
Continuity mistake: As Skipper is untying the ropes from The Galloping Gazelle's body, the ropes change position and the one by his neck (dis)appears.
Continuity mistake: When the bullies put the snake in Courtney's bag, it's brown. When Finley takes it out, it's changed to black, and is also a rubber snake. And when Courtney picks it up, it's real again, and is now yellow.
Revealing mistake: If you look closely, you can see human eyes inside of the mud monster's left eye. Pausing or slowing down is not required or necessary, but is easier to see if you do.
The Scarecrow Walks At Midnight - S2-E14
Visible crew/equipment: In one long shot, a scarecrow is shown walking past doors and windows, trying to break into the house. As the scarecrow nears the only open-draped window, the camera operator is reflected in it. The reflection appears for a short second, only to be blocked out by the scarecrow's bulky figure. (00:03:35)
Continuity mistake: When Cara and Freddy are sliding down in the coffin, Cara is lying back for a few shots, then she's sitting up with her hands holding the sides of the coffin, then her hands are the holding the front, then they're back on the sides for two shots then when they stop, her hands are in front again.
Night of the Living Dummy III (1) - S2-E24
Character mistake: When Zane sees Rocky with the hockey mask, he seems legitimately terrified when he notices him. However, he was responsible for putting him there and no-one else was around. There is no reason for him to express real fear when he planned for his appearance the whole time. (00:11:44 - 00:12:08)
Suggested correction: He only pretended to be scared in order to fool his cousins, uncle and aunt.
Night of the Living Dummy III (2) - S2-E25
Revealing mistake: When all the dummies are set up in Zane's room, you can see in many shots that what is meant to be Zane as a dummy is a complete human.
A Shocker On Shock Street - S3-E1
Visible crew/equipment: Strings are visible on the bats which attack Marty and Erin.
My Best Friend Is Invisible - S3-E2
Audio problem: When Brent is dribbling the basketball, it's very obvious that the sounds of it hitting the ground are not in synch at all with how Brent is bouncing it.
The House Of No Return - S3-E3
Continuity mistake: The moon changes phases during the night that Chris goes into the house. First it's a full moon, then it's a waxing crescent.