Accidental Innuendo: SpongeBob air-humping during his laughing spell in the middle of the episode makes it seem like he's getting... really excited about his jokes.
Awesome Moments: The people of Bikini Bottom calling Squidward out for his cruel prank on SpongeBob, making him realize his mistake.
"April Fools, jerk!"
Also, as their way to get back at him, they help SpongeBob pull off a prank where he reveals they were listening in on Squidward's apology.
"THIS IS AN EXTREME THIRST!"Explanation A line SpongeBob says in his deep voice upon whipping out an inconceivably massive pitcher of lemonade. After "thirsty" emerged as an online slang term for horniness, a screencap of this moment became a popular reaction image for expressing Perverse Sexual Lust towards attractive characters in other works.
SpongeBob's twitchy face after pranking the old lady is a popular reaction image to anything considered Brain Bleach-worthy, usually accompanied by the word "wut".
Tom's drink is often edited to show a bottle of "Horny-Be-Gone" pills.
Tom leaning over to hear SpongeBob's laughter is a very common reaction image.
"You WHAT?!"Explanation Tom's over-the-top delivery of this line, spoken in response to SpongeBob just barely starting to explain the prank he pulled on him, became a popular reaction clip.
"You asked for [X] in your drink, and I only put in [Y]!"Explanation Used as a popular snowclone to explain to someone how a Bait-and-Switch was pulled off on them, with [X] being the expectation and [Y] being the result.
The Woobie: SpongeBob, after he's publicly abused and shamed by Squidward's prank. This even makes everyone else feel sorry for him, including Squidward himself.
Neptune's Spatula:
Fridge Brilliance: When you think about it, Neptune was doomed to lose to SpongeBob from the start. The whole reason he created the Golden Spatula was so he could find a fry cook worthy of cooking for him. If Neptune was able to cook for himself, he wouldn't have created the Golden Spatula in the first place.
Memetic Mutation: "BEHOLD!"Explanation Neptune's initial attempt at displaying his proposed reward to SpongeBob results in him accidentally barging in on Tom Kenny taking a shower. The randomness of the scene led to it becoming a popular exploitable, replacing the clip of Kenny with various other items that Neptune would react in embarrassment towards.