Dirty Pranking Number 2 - S1-E6
Other mistake: Season 1 Episode 6: "Dirty Pranking Number 2". When the pizza delivery man shows up at the police station, the receptionist says that they hadn't ordered twenty pizzas; but the pizza man is holding only eighteen boxes.
Other mistake: When Spike is thrown out of the base by Megatron at the end of the episode, Optimus calls him 'Splik'.
Take Me out of the Ball Game - S3-E24
Other mistake: When Peggy strikes Bill in the head in the softball game, he gets hit on the left side of his head. Later in the scene he is using an ice bag on his head but he's icing the other side.
Other mistake: In the scene where Drakken accidentally "clones" Bonnie Rockwaller instead of Kim Possible, he holds up a picture of Kim to compare the results of his experiment with the real thing. The Bonnie clone, completely encapsulated behind the glass of Drakken's cloning machine (as evidenced by the reflection of light off of it) somehow manages to get a hold of the picture despite this barrier. (She does this without having to break the glass.).
It's About Time! (Part 1 & 2) - S1-E21
Other mistake: Near the end of the episode after they get back, when the camera zooms in on Phineas and Isabella, Isabella's face is gone - only her eyes remain, but after the camera zooms out her face is back.
Other mistake: Tails automatically knows Cosmo's name even before she introduces herself later on (English Dub version only).
Don't Fool With a Phantom - S2-E8
Other mistake: When the wax phantom appears behind Scooby and Shaggy the man who supposedly is impersonating him in the suit is in clear sight directly behind Fred Daphne and Velma.
Heart of Ice - S1-E3
Other mistake: When Batman is watching the security footage of Victor Fries' accident, at first Fries is addressing the camera directly which follows him and pans according to his movements and Ferris Boyle interrupting him, which would suggest a second person was in the room with a handheld camera. But after Ferris Boyle enters the room and orders Fries' experiment terminated, there are several cuts from various angles in the room suggesting surveillance cameras. The surveillance style footage also often conveniently cuts to the face of whichever person happens to be speaking or will cut to a certain angle in order to put emphasis on the action, all of which would require multiple mounted cameras and purposeful editing by either Boyle or one of his subordinates, which would be completely illogical since they don't want anyone to see the footage in the first place. (00:12:20 - 00:13:55)
Other mistake: It appears as if Steve is holding 3 $20 bills when he supposedly received $50.
Hot-Rodding Teenagers from Dimension X - S1-E4
Other mistake: General Traag's weather weapon causes a blizzard across the city, yet when the Turtles and the Neutrinos come up to the surface after the blizzard had been occurring for a while, none of the cars parked on the street, including the Neutrinos' two flying convertibles, are covered in snow. The interior of their cars should have been full of snow.
Other mistake: When LB comes into Tweeg's room and he sees him covered in spots and he is discoloured he freaks out. Why does he freak out? He just saw Tweeg in the previous episode all covered in spots so he should know that it's him.
Moero! Pegasus Ryuseiken - S1-E2
Other mistake: In the ending shot of the tournament bracket showing the potential future opponents, the two saints' names are written the wrong way, as "DORAGON" and "ANDOROMEDA", instead of Dragon and Andromeda. (00:22:00)
Other mistake: While Sonic and Tails are locked up in old Spelunk's cage during the cave-in, right before the huge diamondius crashes on top of the cage, there's a close-up of Sonic holding the bars, and the color of his torso becomes the same as the background mid-shot. (00:13:40)
The Great Egg Heist/The Feud - S2-E9
Other mistake: In the Great Egg Heist, when they arrive at the museum, Jimmy gives everyone shishkabob-shaped earplugs for Libby's scream. But in the next shot, if you look at everyone's ears, there are no earplugs. Also, in the next shot, next to Libby you can see Carl putting his hands over his ears. This is impossible because the pointy ends of the earplugs would stab Carl's hands.
Other mistake: In the voice cast list, the Groom's Father appears twice - with two different voice actors - and the Groom's Mother is not even listed.
The New Kid - S1-E2
Other mistake: At the start when the gang change the time on the clock in the classroom, it wouldn't control the main school clock, plus in every other episode the clock has been operated by The Box on the side of the school, as shown in " The spy who came into the playground".
Other mistake: The Time Expansion Helmet was supposed to allow Dexter to perform his 30 minute morning task in 30 seconds. Since this is the case shouldn't the cat have hit the fishbowl ages ago as time is not frozen.
The Elements of Harmony (2) - S1-E2
Other mistake: At the end of the episode when Princess Celestia is talking to Twilight Sparkle you can see that Princess Celestia's tail is on top of her leg instead of in-between. It's covering her cutie mark.
The End of Flutter Valley (2) - S1-E2
Other mistake: As the Stonebacks begin to destroy the bridge the Ponies call out for help. As the bridge moves up and down, locks of Gusty and Baby Cuddles' hair flash white. Baby Cuddles is also drawn in a deformed fashion with no neck and two rumps.
The Thrice Cream Man/The Flibber-Flabber Diet - S1-E7
Other mistake: In "The Flibber-Flabber Diet," Chowder and Truffles return when Mung calls them. How could they hear him when they'd already left?