Whatever Happened to SpongeBob? (WhoBob WhatPants) - S5-E18
Continuity mistake: Near the beginning, SpongeBob picks up Gary, and some of his slime falls on the floor. When he hugs him and breaks his shell, the slime is gone. (00:01:56)
SpongeBob SquarePants (1999)
1 continuity mistake in Whatever Happened to SpongeBob? (WhoBob WhatPants)
Starring: Clancy Brown, Tom Kenny, Bill Fagerbakke, Rodger Bumpass
Best Day Ever/The Gift of Gum - S4-E20
Revealing mistake: When Squidward says "I suppose if you haven't fixed my clarinet, the concert would have been a bust", Sandy's tail is the same color as her suit.
Dying For Pie / Imitation Krabs - S2-E6
Mr. Krabs: What's the most important rule here?
Spongebob: No free napkins?
Mr. Krabs: No, the other most important rule!
Spongebob: Only discuss the secret formula with Mr Krabs.
Mr. Krabs: As long as you do that, the formula is safe.
Squidward: I thought the most important rule was why do today what you can put off for tomorrow?
Mr. Krabs: But what's today, but yesterday's tomorrow?
Squidward: What?
Question: There was supposedly one episode that ended with SpongeBob, Patrick, Squidward, and Mr. Krabs all laughing in a boat. The laughing then silences, eventually to a stop. Then SpongeBob, Patrick, and Mr. Krabs walk out of the boat, and Squidward eventually walks out too. Which episode is this?
Answer: I believe this is the Season 6 episode "Spongicus".