Continuity mistake: During "Jeopardy", Wakko chooses the category 'United States' for $500. The clue appears on the starting board's lower right corner monitor. Next, there's a closeup shot of the clue, but now more monitors have appeared below and to the right between shots.
Continuity mistake: Before Charlie says to Lola "You must double-triple promise you'll never play with it", he places the rocket beside a black box. Later in the episode, when Lola attempts to get the rocket down to play with it, the rocket is now on top of the black box.
The Crab with the Golden Claws: Part 1 - S1-E1
Continuity mistake: When the three bad guys make for the car after taking Mr. Kuraki with them, two of them are headed for the right hand side and the bad guy with the purple jumper runs to the left side. In the next shot the bad guy with the purple jumper is now on the right hand side of the car, pulling the door shut. (00:06:45)
Emergency Marineville - S1-E11
Continuity mistake: When the second group of Spearhead jets take off from Marineville there are only two jets, but in the next shot you can see three jets, and in the next shot there are two again.
A Case of Overexposure - S5-E8
Continuity mistake: In season one episode 16, Arnold says that him and Willis never met their landlord. In this episode they remember him as Mr Darcy - when they see him they recognise who he is.
Dear Mallory - S6-E3
Continuity mistake: Mallory starts reading one of her advice column letters to Alex. The letter she pulls from the stack is on blue paper in a blue envelope. After a cuts to Alex, there's a close-up of Mallory as she reads the letter, and then in the next wide shot the letter is on orange paper with an orange envelope. The letter is from a girl who intrigues Alex, so he grabs the orange envelope and starts to tear off the return address. The shot changes to show Elyse walk into the room, and Alex is now tearing the corner from the original blue envelope. When Elyse sits down, Alex reads the address holding a slip of the blue envelope, then starts to get up. In the immediate cut that follows, Alex is holding the orange envelope when he stands up. (00:53:50 - 00:54:55)
Heart of Ice - S1-E3
Continuity mistake: When Mr. Freeze's henchman Johnny gets his legs frozen, he is wearing pants and shoes. Later when Johnny is inside a water tank in the Batcave in order to thaw the ice, he has been stripped down to his boxer shorts. While it's possible for Batman to remove Johnny's pants above the freeze-line by cutting them away, he would still have remnants of his pants underneath the ice, but when the ice is thawed, his legs and feet are bare. (00:05:45 - 00:08:05)
Continuity mistake: When Maya sits alone in detention, the door in the corner of the classroom randomly closes itself.
Burple Nurples/Shnitzel Makes a Deposit - S1-E2
Continuity mistake: In "Burple Nurples", Chowder is showing Gorgonzola the Burple Nurples, and there are houses and shops not too far behind Gorgonzola. Later, the camera zooms out, and the buildings are missing.
Continuity mistake: On the school dance KC takes out her earrings and lays them on the table, but when she is locked in the A/V room she has her earrings on. (00:22:17 - 00:23:24)
Continuity mistake: In the cake song, Stingy puts in chocolate but never picks up the bowl. A few shots later, he is now holding the bowl.
Neogenic Nightmare Chapter 4: The Mutant Agenda - S2-E4
Continuity mistake: When Spider-Man is battling the X-Men, he shoots webs at all of them, which they remove. Later when Spider-Man is in Xavier's study with the X-Men, Gambit is shown removing a piece of webbing from his right arm, even though he had already removed it earlier. (00:02:15 - 00:04:30)
The Addams Family Goes to School - S1-E1
Continuity mistake: After Mr. Hilliard goes through gate and nears the house, it's really at the real house. A second later, he's approaching the now-familiar front porch on the studio set. This is easy to tell because the layout of the two porches are radically different.
Field Trip - S6-E6
Continuity mistake: When Roland plays his tape recorder on the coach, the woman on the tape says "lightest lemon sponge I've ever tasted - she used to bake, yes I remember, mind you she worked hard that woman..." But in the cafe Roland didn't start recording until she said "mind you she worked hard..."
Fruit Picking Day/Daniel Is Big Enough to Help Dad - S1-E11
Continuity mistake: The fruit on Miss Elaina's hat changes colors.
Continuity mistake: When Janet gets off the phone with Clarissa's principal, Clarissa is standing on the right side of her friend. The shot changes and she is now on the left.
Continuity mistake: After Molly tries the experiment and takes off her safety googles, they reappear and disappear randomly when she hugs Ed.
Triumvirate of Terror! - S3-E8
Continuity mistake: After Joker subdues the other Amazonians, he is disguised as a female warrior and talks to Wonder Woman and her mother. There are no Amazonians knocked out in front of Joker and one is beside him with her head behind him. But in the reverse angle, that one has vanished and there is suddenly another Amazonian adjacent in front of Joker with her body in a different position. (00:11:10)
Continuity mistake: When Dum-Dum cuts the rope releasing Chug-a-Boom from the balloon, we cut to the car and you can see Clyde and Dum-Dum are surrounded by the rest of the Ant Hill Mob, but when we see the two in the next shot, the other members are nowhere to be seen.
Bug Off/The Crawl Space - S9-E5
Continuity mistake: In Moving Away, Tommy tells the other Rugrats how they first met when Angelica lied about the nasty things they did. However in the Crawl Space, there is a flashback of Tommy, Chuckie, Phil and Lil playing in the playpen when they were younger. Chuckie is scared of the Jack-in-a-box in that flashback, so the Rugrats could not have met for the first time back then.