Continuity mistake: In the episode Welcome to the Chum Bucket, when Plankton is reading a story to SpongeBob, he is interrupted. When he looks up and sees SpongeBob asleep, Sponge doesn't have his Chum Bucket Bucket Helmet on. When Plankton decides not to hit SpongeBob with a mallet and wakes him up, Sponge has the helmet on again.
Continuity mistake: In 'Welcome to the Chum Bucket', the sky is constantly changing in an abnormal way. First, it is daylight when Plankton takes Spongebob into the Chum Bucket. When Spongebob starts singing, the sun is either coming up or going down. When Mr. Krabs starts singing, look through the hole in the wall and the sky looks to be about afternoon. When Spongebob and Mr. Krabs finish their song, it's nighttime.