Pressure / The Smoking Peanut - S2-E12
Continuity mistake: Patrick's popcorn disappears completely after he drops it.
Something Smells / Bossy Boots - S2-E1
Continuity mistake: In Something Smells, when Spongebob is making the sundae, when he says "This sundae is gonna taste great" he has one spoon in his hand, but when he turns around, he has 2 spoons.
Something Smells / Bossy Boots - S2-E1
Continuity mistake: In Something Smells, when Patrick is helping Spongebob outside with the "mirror test", he pulls out the mirror and you see his face to the side of it. In the next shot he is completely behind it.
Mermaid Man and Barnacle Boy III / Squirrel Jokes - S2-E4
Continuity mistake: In Squirrel Jokes, when Spongebob comes out for his second act, there's a back shot of a crowd, and there is one guy in the front right (from the back view) who is green. There is another front shot of the crowd and the guy completely disappears.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: Spongebob says, "We forgot to change the close sign to open," yet when Squidward walks out throughout the episode there is no sign at all.
Continuity mistake: When Tom and Fred are outside the Krusty Krab, Tom is light green, but later in this episode he is dark green. For more info on Tom: http://en.spongepedia.bimserver.com/index.php?title=Tom For info on Fred: http://en.spongepedia.bimserver.com/index.php?title=Fred.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: When SpongeBob is sad because he can't tie his shoes, you see is night. When Gary ties his shoes, suddenly it becomes day.
Mermaid Man and Barnacle Boy III / Squirrel Jokes - S2-E4
Continuity mistake: In "Squirrel Jokes", SpongeBob wants to make a joke about a fork. Someone screams "Forks?" and SpongeBob becomes more nervous. After that, the fork disappears from where it was.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: In "Squid's Day Off", sometimes Squidward's house door opens to the left, and sometimes opens to the right.
The Bully / Just One Bite - S2-E17
Continuity mistake: In "Just One Bite," when everyone says "The only people who don't like Krabby Patties have never tasted one," the kitchen doesn't have a back door. After Squidward says "I gotta have more," he looks in from the back door.
Grandma's Kisses / Squidville - S2-E9
Continuity mistake: In Squidville, Spongebob and Patrick are at the front gate and when Spongebob says, "But you just ate 3 orders of fried oyster skins," Spongebob's teeth disappear.
Survival of the Idiots / Dumped - S2-E8
Continuity mistake: In "Dumped", when Gary takes Patrick's cookie they are in the laundry room. When SpongeBob wants to take Gary for a walk, they instantly appear in the living room. SpongeBob also has a leash in his hand. There is no time for them to walk from the laundry room to the living room.
Pressure / The Smoking Peanut - S2-E12
Continuity mistake: When Sandy and SpongeBob are climbing the mountain at the beginning of "Pressure," when Sandy pushes the rocks down at SpongeBob, there were two big ones holding them that vanish. You could say that she pushed them down too, but remember that they were different colours than the smaller ones. (00:01:40)
Something Smells / Bossy Boots - S2-E1
Continuity mistake: When Pearl gives SpongeBob the new costume for the Krusty Krab, she gives SpongeBob a mirror. In the mirror, Squidward appears and tells him not to accept the costume. If you notice, Squidward is at the LEFT of SpongeBob. Because is a mirror, in the real life he would be at the RIGHT of SpongeBob. When a shot is shown of SpongeBob and Squidward, you can see that Squidward isn't at the RIGHT of SpongeBob, he's at the LEFT.
Procrastination / I'm With Stupid - S2-E19
Continuity mistake: When Janet and Marty (Patrick's fake parents) let go of Patrick's hands in the living room, Marty is on the left. But when Janet and himself pat Patrick, his hand is to the right of Patrick.
Mermaid Man and Barnacle Boy III / Squirrel Jokes - S2-E4
Continuity mistake: In "Squirrel Jokes", right when he comes out of the curtains people put their hands up, but in a front view their hands are down.
Sandy, SpongeBob and the Worm / Squid on Strike - S2-E18
Continuity mistake: In "Sandy, Spongebob, and the Worm," the worm is about twice the height of Sandy and Spongebob. Near the end of the episode, the Worm charges off of the cliff and when he reaches the bottom, and smashes the town, the buildings are tiny compared to him and the sea creatures are microscopic.
Something Smells / Bossy Boots - S2-E1
Continuity mistake: When Spongebob is outside, and he takes out his "to do list" at first he is holding it with his right hand, but when it shows the front of the paper, you see that it is his left hand. Then it is his right hand again.
No Free Rides / I'm Your Biggest Fanatic - S2-E10
Continuity mistake: After SpongeBob sees the "Queen Jellyfish" (really Kevin the sea-cucumber and his friends) he drops his jellyfish call out of his mouth. When it cuts to a wide shot, the jellyfish caller is nowhere to be seen.
Big Pink Loser / Bubble Buddy - S2-E3
Continuity mistake: It seems to me that half the cards that Spongebob used for the card snail have disappeared when Patrick comes in.
Answer: I believe this is the Season 6 episode "Spongicus".