Fools in April

Fools in April is a SpongeBob SquarePants episode from season one. In this episode, Squidward plays a nasty prank on SpongeBob.

Plot
SpongeBob wakes up, and realizes that it's April Fools Day. He begins the day pranking Gary by saying they were going to be peasents and that they were gonna have to move. He then pranks himself into drinking several glasses of lemonade, then goes to work. Squidward looks at the calendar, and realizes that it's April Fools Day, which he says is SpongeBob's favorite holiday. Fearing the worst has to come (or so he thinks), Squidward calls Mr. Krabs saying he's sick and that he couldn't be able to make it to work today. Mr. Krabs says that there's an art collector in his office who wants to buy Squidward's art and name him artist of the month. Squidward immediately rushes to the Krusty Krab, only to find that it was a silly prank by SpongeBob and Mr. Krabs. Squidward attempts to resign from his job, but SpongeBob convinces him to stay, promising not to pull any further pranks on him.

However, SpongeBob continues to prank the customers inside the Krusty Krab while hiding them from Squidward even though Squidward knows he is doing that. The customers seem to take SpongeBob's pranks lightly, because the pranks are considered funny and harmless. Despite the fact that Squidward is not receiving any more pranks as SpongeBob promised, Squidward gets furious over the SpongeBob and the customers' laughter. He decides to plot revenge on SpongeBob by showing him what a "real" prank is, and sets a rope trap with a blob of mustard in the middle. SpongeBob goes to clean it up, and he gets his leg caught in the lasso. Squidward cuts a nearby rope, triggering a chain reaction which sends SpongeBob flying around the restaurant, colliding into several objects and areas. Squidward laughs at him and celebrates his victory, but an emotionally and physically hurt SpongeBob tearfully leaves the restaurant. The customers too are appalled by Squidward's prank, declaring that it was far too harsh to be considered funny. They leave the restaurant, with one of them furious by saying to him "April Fools, jerk," and another one yelling, "YOU SUCK!" Squidward is overcome with sadness, realizing that they were right in that the prank was too harsh and decides that he has to apologize to SpongeBob.

He goes to SpongeBob's house and sees SpongeBob's hat behind a rock. Thinking it's SpongeBob, he goes over to apologize, but then sees that it's Patrick wearing the hat and digging. Patrick tells Squidward that SpongeBob is in the house "impressed" (instead of depressed) and was crying a lot. Squidward feels very sad and attempts to apologize when SpongeBob answers the door, but finds himself physically unable to say "I'm sorry" to him. Eventually, he is able to say it by putting a bubble over his head, so that SpongeBob did not actually hear his apology. Squidward walks away, saying that his conscience is clear, but is confronted by memories of what he did, feels guitly again, and goes back and genuinely apologizes to SpongeBob, but tells SpongeBob not to tell anyone. SpongeBob forgives him, but then fully opens his front door, revealing that everyone else is inside behind him, and witnessed Squidward's apology. They all say "April Fools!" to Squidward, who is flabbergasted by this. He states that he was fooling them as well before running away, laughing maniacally.