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.
Pizza Delivery / Home Sweet Pineapple - S1-E5
Continuity mistake: After Spongebob's house is gone, Squidward boo-hoos and goes into his house, then sounds happy. He starts throwing streamers and confetti out of his NOT-OPEN porthole. If the porthole was closed, they wouldn't fly out. Similar to some other ones in this show, and one in Fairly Odd Parents.
Culture Shock / F.U.N. - S1-E10
Continuity mistake: When SpongeBob and Plankton jellyfish,SpongeBob catches a jellyfish with no spots. Then it shows the jellyfish with spots or vice-versa.
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.
SpongeBob Meets the Strangler / Pranks a Lot - S3-E20
Revealing mistake: In "Spongebob Meets The Strangler" when that fish holds up Spongebob's dry cleaning at the supermarket, it looks like he is holding it up with a coathanger because his hand is up in the air, but you can easily see nothing is holding it up. It's just floating up in the air.
Suggested correction: The clothes are being held up by a coat hanger. It may be hard to see due to it blending in with the wall color, but if you look closely, it's there.
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.
Sandy's Rocket / Squeaky Boots - S1-E8
Continuity mistake: When Pearl is opening her present the cake disappears.
Culture Shock / F.U.N. - S1-E10
Revealing mistake: In "Culture Shock" when Spongebob takes the green fish's order, he has a pencil tucked in his ear, but he doesn't have an ear, so it's just floating in thin air. (00:01:55)
The Sponge Who Could Fly (aka The Lost Episode) - S3-E16
Continuity mistake: On the news one fish had hair. Later it was gone.
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.
Continuity mistake: In the scene where Mr. Krabs is saying "this is no game" Spongebob is in his underwear, then it goes to Mr. Krabs and back to Spongebob and he's in his work clothes.
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.
New Student Starfish / Clams - S3-E14
Continuity mistake: In the episode New Student Starfish., SpongeBob's good noodle stars changes number throughout the episode.
You Wish ('Shanghaied') / Gary Takes A Bath - S2-E11
Continuity mistake: After Squidward comments about how the ship is dirty, he continues to climb up the anchor rope. Once he's out of the shot, the rope immediately changes color.
The Graveyard Shift / Krusty Love - S3-E13
Continuity mistake: In "Graveyard Shift," when Squidward says to that guy they think is the hash-slinging slasher, "If that was you on the phone and you on the bus, then who was flickering the lights?" look at the "order here" sign. It says "order hear" instead of "order here," which it reads in previous shots during this episode.
The Chaperone / Employee of the Month - S1-E12
Continuity mistake: Spongebob says that this is the 27th award he has won, yet when he is standing in front of the pictures there are at least 30.
New Student Starfish / Clams - S3-E14
Continuity mistake: When SpongeBob and Patrick arrive to the class, SpongeBob writes Patrick's name in the board. Notice that he writes it in capital letters: "PATRICK". After, when Patrick is asked to say his name to the class, and he becomes nervous, look at the board, at Patrick's name: now isn't in capital letters, is normal: "Patrick".
Mermaid Man and Barnacle Boy III / Squirrel Jokes - S2-E4
Continuity mistake: In "Squirrel Jokes", when Spongebob tells the joke about Squirrel in the second act she's at a table alone, but in the next wider shot there's a chair next to her.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: In Your Shoe's Untied, when Spongebob takes the patty to Squidward, it's just a patty with lettuce, but in one shot, you can see cheese and pickles on it.
Continuity mistake: In the morning when they all wonder where Santa is, and Spongebob keeps singing "Santa's coming tonight", once everybody walks away, Patrick appears right next to Spongebob.