The Algae's Always Greener / Sponge Guard On Duty - S3-E7
Continuity mistake: In "The Algae's Always Greener", after Squidward barges into Mr. Plankton's office, you can see that there are no krabby patties on Mr. Plankton's desk, but when it pans back to Mr. Plankton's desk, there are two krabby patties on his desk. (00:07:35)