Hall Monitor / Jellyfish Jam - S1-E7
Continuity mistake: When SpongeBob asks Squidward to play his clarinet better, he is wearing his night shirt which is purple, but in the next shot he is wearing his normal shirt which is brown.
Jellyfishing / Plankton! - S1-E3
Continuity mistake: The words "Total Control" constantly appear and disappear from the controlling device in Spongebob's brain.
Sandy's Rocket / Squeaky Boots - S1-E8
Continuity mistake: In "Squeaky Boots", Mr. Krabs starts hearing squeaky sounds everywhere. Then he goes mad, and says he took the boots from SpongeBob. In this point, notice of the restaurant floor's color. Mr.Krabs somehow lifts the whole restaurant but we can still see some floor (where Krab is). Notice that now the color of the floor has changed.
Revealing mistake: At the beginning of Rock Bottom, when the bus pulls up in front of Patrick and SpongeBob, right before Patrick steps up onto the bus, SpongeBob's right arm is missing and it suddenly appears as he starts moving.
Revealing mistake: Near the end of "Rock Bottom", when SpongeBob arrives back to Bikini Bottom, SpongeBob's pineapple is animated differently from the other buildings. It looks like it was cheaply tacked on in post production.
Help Wanted / Reef Blowers / Tea at the Treedome - S1-E2
Revealing mistake: When Spongebob uses his binoculars, his teeth turn yellow for one frame.
Help Wanted / Reef Blowers / Tea at the Treedome - S1-E2
Character mistake: In "Help Wanted", Stephen Hillenburg's name in the "Written By" section of the title card is incorrectly spelled as "Stephen Hilleburg."
Help Wanted / Reef Blowers / Tea at the Treedome - S1-E2
Revealing mistake: In the shot where Spongebob says, "That little squirrel is in trouble, " half of his belt is missing.
Revealing mistake: After SpongeBob disguises himself as Patrick's rock and right before he sneezes his uvula clips through his bottom lip.