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.
La Behemoth - S1-E54
Continuity mistake: As Marita walks over to the washing machine with a stack of clothes, its round door opens automatically between shots.
Continuity mistake: When Beavis is getting the idea to use the plate as a discus, the amount of cookies on the plate varies depending on the shot.
Rocko's Happy Sack / Flu-In-U-Enza - S1-E11
Continuity mistake: Rocko's Happy Sack: Rocko scans all of his groceries in the checkout lane. Then, when Filbert tells Rocko that his total is $150, the groceries have disappeared from the counter. They reappear when Rocko finishes shouting at Filbert, then disappear again in the next shot. (00:11:09)