Big Pink Loser / Bubble Buddy - S2-E3
Revealing mistake: Big Pink Loser: When Patrick says, "Why can't I do anything right?", and starts hitting his broom on the floor, the drinks that are supposed to be on the customers' tables are instead layered behind them. (00:05:18)
Big Pink Loser / Bubble Buddy - S2-E3
Revealing mistake: Big Pink Loser: When Patrick is answering phone calls, the third time he picks up and says, "No, this is Patrick", the anchor symbol on his hat vanishes for one frame. (00:04:36)
Suggested correction: This mistake can only be detected by freezing the film and advancing frame by frame. It is not visible while watching the film at a normal running speed. According to the rules of this site, this invalidates the error.
This is not true. You can see it disappear if you watch it at normal speed; it does not require pausing at all. At least, I am able to see it.
Procrastination / I'm With Stupid - S2-E19
Other mistake: I'm With Stupid: When Patrick and his "parents" make fun of Spongebob because they believe he's stupid, he gets so frustrated that he runs through the wall, leading him right outside. This makes no sense, because they are in Patrick's house and the inside of it is underground.
SpongeBob Meets the Strangler / Pranks a Lot - S3-E20
Other mistake: Pranks a Lot: When everyone is cheering on Spongebob and Patrick at the end, Sandy whistles by putting her hand through her helmet. Impossible.
The Thing/Hocus Pocus - S4-E16
Continuity mistake: The Thing: When Squidward is riding his bike on the road, he hits a cement truck, and gets covered in cement. He tries to get out of it, and a shot later, the location suddenly changes from the road to a green hill.
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.
Have You Seen This Snail? - S4-E3
Revealing mistake: After SpongeBob tells Patrick, "I can't find Gary," text that reads "Rough Draft Korea" briefly appears on screen during the bubble transition. (00:08:24)