Continuity mistake: Wolverine first enters the sewers by ripping away a fence in the subway. When Jubilee and Gambit follow him, the fence is still intact. When they get closer it is torn again. Odd, really, because on the whole this show has few continuity errors, like self-mending clothes in other cartoons.
Continuity mistake: The explosion that scars Harvey Dent and creates Two-Face is shown to have scarred and colored him light blue on the entire left half side of his face and neck. However, when he is first shown in the hospital, the parts of the left side of Harvey's face that aren't covered in bandages are still normal, as is his entire neck. (00:19:35)
Continuity mistake: In the episode where Fester invents a fabric: When Fester lies down on the parking lot, his head is first pointing upwards, towards a car, then in the next shot he has turned 90 degrees and his head is pointing towards Norman's legs.