Continuity mistake: When Spongebob and Patrick have run away, when they are fighting about the chocolate, Patrick has chocolate all over his mouth. Patrick says something like "I'll get there first" and starts running after Spongebob, and in the next shot his face is completely clean.
Continuity mistake: When Gary and Spongebob are waiting at the door, there is a sign behind him that says "pin the tail on the horace" (yes it says horace), and there is one tail hanging up, but when everybody comes in there are suddenly two.
Add timelogan crews
Continuity mistake: When his pants fall off when he's trying to hide, his pants are hooked to the plant by the brown part of his pants, but when Sandy comes looking and she sees his pants on the plant, they're hooked by the white part.
Continuity mistake: When SpongeBob and Patrick had used the reef blower to take parts of Squidward's house off, they had taken off all parts but the two ear-like parts on the sides of the house. When Squidward demands that they put the parts back, the ear parts are no longer on the house, but are being blown back onto the house. This isn't possible because they were never taken off in the first place.
Continuity mistake: In 'Welcome to the Chum Bucket', the sky is constantly changing in an abnormal way. First, it is daylight when Plankton takes Spongebob into the Chum Bucket. When Spongebob starts singing, the sun is either coming up or going down. When Mr. Krabs starts singing, look through the hole in the wall and the sky looks to be about afternoon. When Spongebob and Mr. Krabs finish their song, it's nighttime.