
Grandma's Kisses / Squidville - S2-E9
Other mistake: Grandma's Kisses: After Grandma pulls the plug from the floor, she kisses SpongeBob and says that he can kiss his Grandma and still be an adult. In this shot, SpongeBob's legs are completely missing. His pant legs also vanish and reappear mid-shot, and even his legs appear for a frame or two, then vanish. (00:11:48)
Grandma's Kisses / Squidville - S2-E9
Other mistake: At the end of Grandma's Kisses, Harold "Bill" is olive green.
Jellyfish Hunters / The Fry Cook Games - S2-E16
Other mistake: When Patrick takes off Spongebob's right shoe to lick, his foot appears to be his left, not his right. (00:22:05)

Sandy, SpongeBob and the Worm / Squid on Strike - S2-E18
Other mistake: Squid on Strike: When Squidward looks at himself in his bathroom mirror, his buttons are on the left side of his pyjamas in the reflection. When he is shown in bed a few seconds later, the buttons are on the same side; the reflection was not reversed. (00:09:07)
Sandy, SpongeBob and the Worm / Squid on Strike - S2-E18
Other mistake: Squid on Strike: When the destroyed Krusty Krab is first shown, the broken Krusty Krab sign has some of its letters scattered around it. There are two Ts still attached to the sign, but there is another T on the ground right next to the sign. This is impossible because there are only two Ts in "The Krusty Krab." (00:11:25)
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. (00:21:35)






Answer: I believe this is the Season 6 episode "Spongicus".