"April Fools" is the twenty-first episode of Season 2 from The Penguins of Madagascar.
One morning in the Lemurs' Habitat, King Julien realizes that his fudgy pops are gone. Maurice said he didn't eat them and Mort also said he didn't, but King Julien knew he lied because there is fudge pop stain on his face. Mort tries to give a good explanation why he ate the fudgy pop, but just said "April Fools!". Maurice tells Mort that April Fools ain't gonna fly. King Julien asks Maurice what April Fools (which King Julien pronounces "April F'ue'ls") means. Maurice can't believe that King Julien doesn't know about April Fools. King Julien asks him if he heard of January Jacks, but Maurice knows he made it up. King Julien explains that Christmas Steve is real (but it was supposed to be "Santa Claus"). Mort pops up from behind the counter saying that "Steve" knows if he's been bad or good. He lowers himself slowly saying "And that's creepy!", meaning that "Steve" knowing if everyone's been bad or good is mysterious. Maurice explains that April Fools is a holiday where people pull pranks on other and before they get mad, people say "April Fools!" to them. King Julien decides to try it, but Maurice explains that it only works on April 1. King Julien said he didn't know about it so he decided to proceed.
In Burt's habitat, King Julien gives Burt peanuts. Burt sucks them and eats them, but finds them spicy and sneezes fire. King Julien explains that they're Jalapeño (Ha-la-pe-ño) Peanuts and says "April Fool's!". Next, King Julien tries to trick Maurice in stepping on a red X on the ground. Maurice refuses until Mort does it. A second later, a big crate drops on Mort. King Julien prepares to save him, but tricks Mort by saying "April Fools!" and squashes Mort again.
In the Penguins' Habitat, Skipper and Kowalski tell Private and Rico that a truck full of fish will pass by the Zoo Gates at approximately 14:00 hours (2:00 PM). As Kowalski explains what "Operation: Snare the Car" will require, King Julien screams and said that Roger is having him for dinner. As the Penguins jump in the Lemurs' Habitat, King Julien says "April Fools!" and Roger said that he didn't know about the prank. Roger leaves frustrated. Skipper tries to explain that it's not April 1, but King Julien explains about the King Julien Calendar. The Penguins return to their operation, but King Julien screams and says he needs some genuine helping. The Penguins jump in again, but as they land, their butts slipped on a puddle of oil and sled off the edges. Skipper threats King Julien not to prank them again or they will do something horrible to him. The Penguins wait for a scream from King Julien and after a few seconds of waiting, they continue the operation, but King Julien screams that he's on fire. Private believes it's a real emergency, but the rest think it's a prank. After some screams to fool the Penguins into coming out, they peek through the fence until King Julien throws fruit at them.
Back at the Penguins' Habitat, Skipper can't take it anymore. Kowalski plans to get even by performing a prank involving itching powder and fake vomit, but Skipper thinks King Julien will plan something involving these things. Skipper throws the itching powder away, but it hits Rico in the head and it sprays him as it landed on the ground, causing him to itch. Skipper then decided to start "Prank Resistance Training".
Soon, Skipper pulls off gags at Private, Kowalski and Rico, which they don't know about. When Private prepares to sit and enjoy his two-scooped snow cone, he sat on a whoopee cushion. When Kowalski steps out of the door, a bucket of fish dropped on him. Skipper offers Rico a can of fish, but when he opened, rubber worms popped out, causing Rico to accidentally spit out a bomb and it explodes. Private prepares to sit and enjoy his lollipop and removes the whoopee cushion, making Skipper proud and decides to take a picture, but Skipper reveals it blasts water. Kowalski tries to watch out for a falling bucket, but nothing happened, making Skipper was proud and offers him a bucket of fish, but as Kowalski reaches in, his flipper snaps on a rat trap. Rico keeps his eyes away from the can of fish popping out rubber worms so he won't be surprised, making Skipper proud and offers him a handshake, but shocks Rico with a joy buzzer.
Meanwhile, at Roy's Habitat, Roy was enjoying his nap, but turns around at King Julien and asks him what he's doing. King Julien says he ruined the picture, but reveals he drew a rude rhino face on his butt in permanent red marker. Roy becomes furious, but King Julien tries to calm him down by saying it's an "April Fools" prank and runs away, but Roy is still furious.
Back at the Penguins' Habitat, Skipper tests the results of Private, Kowalski and Rico's Prank Resistance Training (and Private said he didn't like the "Wet Willies"). Skipper takes off fake glasses, fake nose, fake eyebrows and fake mustache and says that they completed their Prank Resistance Training. Private, Kowalski and Rico cheer and Skipper says he's proud. Skipper tricks Private by saying he has a stain on his body and has as he looks down, Skipper slaps him (again, but not on the cheek, on his lower beak), as a reminder that pranks can happen anytime anyplace so they need to stay strong. Skipper tricks Private again about a stain on his his body and slaps him on the lower beak again. Skipper continues to trick Private and Private tries to resist looking at it & begins to whimper, hoping Skipper wouldn't get him to look.
Meanwhile, while King Julien, Mort and Maurice are walking back to their habitat, King Julien explains that he fooled the chameleons by tying their tongues together, making them turn into an odd color. Maurice tells King Julien to give it a rest, but King Julien refuses. King Julien prepares to jump on his on his Bounce House, but (just like in Jungle Law) slams on it, deflated, but this time, hurt, because we hear him talking in pain and twitching his body in pain (unlike in Jungle Law, King Julien just complains about it deflated). Maurice saw that a big hole is poked on the Bounce House. Roy slams his horn on the habitat metal wires and the Lemurs look. Roy says that the next hole he'll punch is through King Julien. Maurice then knew it was Roy who poked the hole.
Back at the Penguin's Habitat, Skipper continues testing Private by tricking him that there's a stain on his body and Private continues to hold it & continues whimpering until King Julien screams. Skipper faces away and Private looks at it, seeing there's no stain and relieved that Skipper didn't slap him. King Julien comes from the passage behind Private's 1st Prize (a wooden board with a big fish and a tag saying "Private's 1st Prize") and tells them that Roy is out to get him. Private was about to think that it's a real emergency, but soon thinks it's a prank. King Julien tries to convince them that's he's not pranking them, but Skipper resists and says, "Do we look stupid to you?" and after King Julien insults their eyebrows being "heavy", Skipper kicks him out of the Habitat. After King Julien insults their "ridiculous" wings, Skipper shuts the hatch. Roy slams his horn on the fence bars and King Julien runs away.
King Julien enlists Burt to help him, but Burt thinks he's pulling another prank on him. King Julien demonstrates on what he'd do if he was pulling a prank: tricking him that there's a mouse. However, Burt is convinced and accidentally stomps King Julien 3 times before leaving. Roy slams his horn on the habitat's metal wires and King Julien starts running again. King Julien tries to run away, but slams on Roy's nose. He tries to hide behind his tallest horn, but Roy knows he's there. King Julien tries to convince him that he's done pranking, but when he says that he'll pull one unless it's funny, Roy blows his nose at King Julien and lands a few feet away and says he'd double-done. Roy starts charging, but King Julien hides. Roy runs by some trees. Roy slams his butt on the tree bark and King Julien drops on his horns. When King Julien says he's letting anger getting in his life, Roy throws him to a wall. Roy starts charging, but King Julien runs on the high wall and taunts Roy that he'll never reach him, also saying he'll run forever, but he falls on the edge. Roy prepares to land a blow, but Skipper and the Penguins show up. Private, Kowalski and Rico fire sleep grenades at Roy. Roy dodges two, but gets hit with one and falls asleep in front of Skipper.
The Penguins want to make sure King Julien has learned his lesson, but King Julien keeps getting it wrong (like saying he's learned that the Penguins will rescue him no matter how "jerky" he is to them, a stitch in time says 9 or 8 or 10). Roy wakes up and prepares to charge, with King Julien too caught up trying to learn his lesson, he doesn't notice Roy. Skipper pushes King Julien out of the way and prepares to sacrifice himself. King Julien opens his eyes and saw that Skipper took the blow. King Julien grabs Skipper and sadly comments about why does it have to happen to someone like Skipper. When King Julien notices plush, Skipper says, "April Fools, Ringtail!", revealing that King Julien was holding a Penguin Plushie. Skipper is proud of Kowalski's switcheroo. Kowalski says, "In your lemury face!" and Rico teases him. The Penguins, Mason, Phil, Burt, Roger and Roy all laugh. King Julien says he'll tell "Christmas Steve" on all of them. Mort pops up and said again, "Creepy!" before lowering himself (again).
Skipper is proud to turn the tables and Private tricks him that he has a stain on his body. When Skipper looks, Private slaps his lower beak and laughs at his face, tricking him. Kowalski and Rico looked puzzled. Private continues to laugh as he and Skipper started walking. After Private said, "In your face!", Skipper slaps him (again, but off-screen), making him say, "Ow!".