Continuity mistake: Throughout the whole episode of "Missing Identity", SpongeBob's shirt is backwards. This is seen with his sleeves being supposedly behind him. The sleeves are missing from the front, which is normal, but throughout the episode, pay attention to behind SpongeBob. His sleeves are supposed to be behind him, but are missing altogether.
Other mistake: Mr. Krabs pours Sandy's growth serum on a patty. It grows, and Spongebob scrapes some off to construct individual patties from the larger one. The larger one then continues to grow, but the individual ones do not, even though they are all the same meat.
Plot hole: In the end of "Pranks A Lot" SpongeBob and Patrick glue the door shut in order to keep Mr. Krabs inside the Krusty Krab. When SpongeBob And Patrick are visible again, it turns out that a lot of customers have entered the Krusty Krab to see SpongeBob and Patrick naked. All of those people had no way to get into the Krusty Krab with the doors glued shut. It can't be that they broke down the doors, as they're still there.ryderpoints
Continuity mistake: When Mr. Krabs comes upon an elderly person, the old man tells him to wait in line like everybody else, and then Mr. Krabs sees a bunch of elderly people waiting in line in front of a cemetery. Seconds later a man handing out ice cream to the elderly people suddenly appears in front of the entrance.Kaiser Strien
Character mistake: In the beginning of "One Krabs Trash" Spongebob only has one bill in his hand, a 5 dollar bill. When he goes to his house and comes back, he says he found 68 cents. Therefore, he has 5 dollars and 68 cents. However, he has two dollar bills and a few pennies in his hand, which cannot be made into $5.68.