April Fools' Day



A long time ago, April 1st was the start of the new year, and after it was officially changed to January 1st, people who still celebrated at the old date were dubbed "April Fools". Or possibly the term originally referred to people who prematurely celebrated the start of summer (which was traditionally May Day, May 1, in many ancient cultures); the exact origin is unclear. Regardless of where the term originated, it has since become something much sillier.

April 1 is known as April Fools' Day, where almost every single person in the world becomes The Fool. A time to trick Muggles that the joke is real, and a time to pull pranks and tricks. You will then reveal the trick with the line "April Fools!"

Within fiction, characters will often play tricks on each other, and will often get into escalating competitions to play the best trick on each other, or catch each other in the most embarrassing lie.

Many works of the media include April Fools' Day jokes: usually articles presented as news or truth that go beyond the limits of sense, contain blatant inaccuracies, would be completely outrageous etc. They usually assume Viewers Are Geniuses and that no one would be stupid enough to take it seriously, but of course that's not always true. People are often taken in, get outraged, get laughed at, get to made feel stupid. A good time is had by all.

In the 1990s and early 2000s, a common April Fools' Day Joke on Web Comics was for two different webcomic authors to each do the other's strip. By far the most popular joke on the Internet seems to be a claim by the owner that the website is shutting down. A common joke specific to fansites is to suddenly denounce what the fansite stood for and revamp it to focus on a different franchise, most commonly one that bears similarities to the original, or even a competing one. Another joke specific to gaming sites with free content is the introduction of a "premium" version of the site, where it's said one gets exclusive content if one pays for it; generally, the site makes "preview content" available, with most of the "premium perks" turning out to be silly (or duplicates of free services by other sites devoted to the game).

Subversions of April Fools' Day is to have something improbable published on that day be actually true (either on that day or on a later date, or when a prank goes just a little too far).

In any case, woe betide someone who dies (or worse, is born) on April Fools' Day. And god help you if a natural disaster happens and people think the blaring sirens are a prank.

Of course, television has shown some April Fools Day-themed episodes, especially that focuses on the day as a basis of the plot. See April Fool's Plot for more information.

Anime & Manga

 * Axis Powers Hetalia usually has an event on the author's blog where one of the characters takes over the site for the day.
 * In 2003, mahq.net made an April Fools' Day prank announcement of a Gundam Seed sequel, which some websites in Japan apparently thought was a genuine one. And when Gundam Seed Destiny was released, the uncanny similarities just made it funnier.
 * In addition April 1st is the site's anniversary, meaning they generally don't do April Fools' Day jokes. That, and it's admittedly kind of hard to top Grandiose Gundam.
 * In 2010, promotion for the upcoming Gintama movie was changed so that Shinpachi appeared to be the main focus. Worth it for Gintoki's expression in the cutaway panel alone.
 * In 2012, Adult Swim actually resurrected CN's much loved Toonami block for one night only, with all new recorded lines from TOM 3, airing episodes of nostalgic anime like Trigun, Outlaw Star, The Big O, Dragon Ball Z, and some a few other anime that had previously aired on both Toonami and Adult Swim.
 * This case is notable because fan reaction was so overwhelmingly positive and widespread that Cartoon Network actually revived the block.
 * In 2012, Crunchyroll announced a new streaming app for Game Boy. The original Game Boy.

Comic Books

 * In 2005, Wizard magazine announced that Geoff Johns was working on a Vertigo Comics version of Captain Carrot and His Amazing Zoo Crew, in which the Crew was disbanded, Little Cheese was murdered by one of his teammates, and a new character called the Bald Eagle had to bring them all back together. Then Johns topped this by actually writing it into an issue of Teen Titans the following year.
 * In 2009, the big news on the comics blogsphere was Johns again, now working on Vibe: Rebirth with Ethan Van Scriver. At last, one of the most iconic characters in the DC stable is brought back to glory!
 * For those who don't follow DC, Johns has done "Rebirth" stories for Green Lantern (Hal Jordan) and the Flash (Barry Allen) and is set to do one soon for Superboy. Vibe is obviously a less prominent character.
 * in 2010 Top Shelf Productions released a cover for The League of Extraordinary Gentlemen1988 featuring among others Doc Brown and Sergeant Bosco "B.A." Baracus.

Live Action TV

 * The BBC's Panorama made a show about "spaghetti trees," leading to many viewers asking how they could grow their own.
 * The BBC also produced a feature showing a recently discovered breed of penguins which flew to the jungle in the summer.
 * A Discovery Channel program played perfectly straight, that proved that yes, in fact The Earth Really Is Flat.
 * The Drew Carey Show made a few April Fools' Day episodes in which there would be various oddities occurring in the otherwise typical episodes (snow falling on set, mispronunciation of names, the ultrasound baby in the Mohawk Productions Vanity Plate meowing instead of giggling, etc...), which are never brought up again. ABC made these into contests as to who could spot them all. Keep in mind that the major plot points of those episodes have been brought up again, such as Mr. Wick's Groin Attack, so those at least are canon; when rerun, each error is pointed out Pop Up Video-style.
 * GSN (Game Show Network) did a major host switch on April 1, 2003 among its original programming. Marc Summers hosted Cram, Todd Newton hosted Russian Roulette, Graham Elwood hosted Whammy: The All-New Press Your Luck, Mark L. Walberg hosted Friend or Foe and Lisa Kennedy Montgomery hosted Win Tuition. The five hosts came together for a charity episode of Lingo, which also had Todd Newton announcing (and Mark and Marc curb-stomping Graham and Kennedy 500-0).
 * Speaking of game shows, Wheel of Fortune and Jeopardy! both partake in this:
 * 1997: Jeopardy! host Alex Trebek and Wheel host Pat Sajak traded places. Pat and co-host Vanna White also played Wheel that day, with Pat's wife, Lesly, at the puzzle board. The flip-flop was Lampshaded heavily on both shows: Jeopardy! had Wheel-themed categories in the first round (such as "Buy a Vowel" and "Before & After," which later became a recurring category on Jeopardy! itself), and "fool"-themed categories in the second, and a Final Jeopardy! category of "Trinidadian Amateur Ichthyologists." Wheel had several gag puzzles, including TRADING PLACES as the Bonus Round answer.
 * 2008: Alex wore a fake mustache (he had shaved off his trademark mustache by this point), and Pat tricked Vanna into believing he was bald by wearing a real wig over a bald wig.
 * 2010: Wheel made 10 things wrong with the show. They invited viewers to print out a worksheet from their website, and write down what they thought were the correct answers. Some were obvious (i.e. the Bankrupt wedges having "Bankrut", the Polish translation of that word), some weren't (Pat wearing a stud earring in the second round), and an eleventh wasn't even pointed out (rodeo footage in the opening montage of Hawaiian activities corresponding to the rest of the week's Hawaii theme). Jeopardy! spliced in different hosts for Alex Trebek on the same day. Alex still read the clues, but Pat Sajak walked out at the top of the show, Neil Patrick Harris was spliced in during the first round, Jeff Probst (who once hosted Rock & Roll Jeopardy! before his Survivor fame) during the second round, and a clip from Saturday Night Live's Celebrity Jeopardy! sketches featuring Will Ferrell parodying Alex Trebek. There was also an "April Fool!" category concerning joke articles published during the month of April (such as the Veterinary Record's "Brunus edwardii" article).
 * 2011: Every puzzle on Wheel (except the Bonus Round) had the word "fool" in it. Amazingly, the contestants never caught on; you'd think by the third round, they would've been calling L and F, then buying an O.
 * The Price Is Right has a long history of making gag prize Showcases with obviously silly prizes (e.g. egg beaters and paper plates, "six new cars" that turn out to be Matchbox cars, or even an acute case of athlete's foot as a prize). On another episode, the door that host Bob Barker normally walked through revealed a sign that said "April Fools!" before Bob walked onstage through the audience.
 * Drew Carey, after taking over as host on Price, has made several April Fool's gags on each April 1 episode. Except for 2011, he brought in Kathy Kinney, who reprised her role of Mimi Bobeck from The Drew Carey Show. He also does several funny gags throughout — things like playing the Match Game music during the credits, having everyone wear nametags that say "Pat", having random sound effects play during the Showcase Showdown instead of the normal ones, etc.
 * For 2011, the gag was that the 10,000th...something was going to happen today, so it was an important episode. Too bad so many things went wrong, from pieces of the set falling apart or malfunctioning, to announcer George Gray getting hit by a tennis ball launcher. And the 10,000th thing didn't even happen.
 * Cranked Up to Eleven as a prank on Tom Bergeron for the Hollywood Squares episode taped to air on April Fool's Day 2003. At one point the male and female contestants were engaged in a heated argument, after which the male contestant made the female contestant break down in tears. Bergeron, who had a deer-in-the-headlights look (but, according to his book, wasn't going to stop no matter what), comforted the "poor woman" as he sent the show to commercial (of course, unbeknownst to him, the camera was still running). At the end of the episode, giggling executive producer Henry Winkler (who was also filling in as announcer at the time) said over the intercom, "Hey Tom...April Fool's." Apparently, Bergeron hadn't realized the airdate of the show...until then.

Magazines
"How can we put this gently? The test subject, Dr. Dru Wiliamskini, has a new nickname: "Steaming Puddle of Goo." Better luck next year!"
 * Doctor Who Magazine has had several, including a claim that the Doctor Who story "The Tenth Planet" was meant to be in colour (years later The Television Companion was still explaining that this wasn't true).
 * A sort of accidental subversion: SFX claimed in April 2010 that William Hartnell was going to be in "The Eleventh Hour". No-one was more surprised than the SFX crew when he was (through the magic of Stock Footage), along with the other Doctors...
 * Nintendo Power does this a lot:
 * 1997 ran phony newspaper clippings, one of them saying that the Headless Snowman from Super Mario 64 was getting his own game instead of Luigi.
 * 1999 had an article featuring Pikachu from Pokémon as a Y2K expert. However, his advice was completely useless since all he ever spoke was the iconic Pokémon-Speak. The authors eventually turn to Bill Gates himself...who unfortunately also speaks in Pokémon Speak.
 * 2001 discussed "Warp Pipe Technology", a fake Defictionalization of the warp pipes of Super Mario Bros.. fame. At least two readers were fooled and wrote in to ask about the technology; their response:


 * There was also the infamous Zelda April Fool's joke, showing fake screenshots of Link holding the Triforce. This only further fueled rumors of secret ways to get the Triforce, even after Nintendo repeatedly explained it wasn't possible.
 * GamePro had an annual April feature called "LamePro", which mostly featured crude reimaginings of the hot games of the day, along with some mashups like "Barney and Friends Butthead" and "Street Fighter Alfalfa".
 * Electronic Gaming Monthly was so good at this, they ended up creating Urban Legends Of Zelda out of most of them. They are described in detail in the aforementioned article, but for the sake of summarization:
 * 1991: Simon Belmont in Teenage Mutant Ninja Turtles II: The Arcade Game.
 * 1992: Sheng Long in Street Fighter II.
 * 1993: Four fake games for the Atari Jaguar.
 * 1994: Streeets of Rage 3 (allegedly)
 * 1995: Nintendo publishing a Sonic the Hedgehog game.
 * 1997: Sheng Long in Street Fighter III.
 * 1998: "All Bonds" cheat in 'GoldenEye 007''.
 * 1999: The GameShortz, which was just boxer shorts with PlayStation controllers attached.
 * 2000: The return of the Intellivision.
 * 2001: Sega selling Sega Neptunes.
 * 2002: Sonic and Tails in Super Smash Bros.. Melee (this became Hilarious in Hindsight when Sonic made it into Brawl).
 * 2003: Dead or Alive: Extreme Beach Volleyball nude code.
 * 2004: Lord of the Rings racing games.
 * 2005: The Legend of Zelda the Wind Waker getting a The Legend of Zelda Twilight Princess makeover.
 * 2006: The iGame.
 * 2007: Mushroom Kingdom Hearts.
 * 2008: Lego Adaptation Game Halo. (Ironically, there are Halo Mega Bloks.)
 * 2010: Call of Duty: set in The American Revolution.
 * Game Informer has a section in every April issue called "Game Infarcer", complete with a faux cover and mini-articles poking fun at various aspects of the gaming world. In each May issue, GI publishes a few choice letters from people who believed the jokes to be real, despite the fact that every Game Infarcer page has "PARODY" in capital letters at the bottom. Interestingly enough, in 2010, most of the objections were not to the articles, but fake Editor-in-Chief Darth Clark's declaration that his game reviews had surpassed actual games as an art form.
 * In 2008, Hot Rod published an article proclaiming the revival of American Motors (bought by Chrysler in 1987). The article contained detailed information and drawings of forthcoming models including the AMX, Matador, Ambassador, Pacer, and Gremlin. It was later revealed to be an April Fools' Day joke.
 * Road & Track usually prints a review of something other than a car, but a mode of transportation none the less.
 * In their April 2012 issue, Car And Driver listed 25 cars that would be released within the next few years. Most of them were real, except for the Chrysler TD By Maserati.

New Media

 * On 1st April 2008, during the height of the Rickrolling craze, YouTube linked every front page video to the infamous Rick Astley song. Kongregate pulled a similar trick.
 * On 2009, YouTube stole a page from Homestar Runner and flipped the site (and videos!) upside down. This lasted even beyond the date itself with a URL suffix. However, it didn't always work (For example, if you're using a YouTube userscript for the Greasemonkey add-on for Firefox.).
 * Some videos also weren't completely fixed afterward and will flip upside down when put into high quality.
 * For 4/1/2010, Youtube put a "text-only mode", displaying certain videos as entirely made of text in various colors—including nearly any video with resolution greater than 360p, not just videos YouTube had done manually. This effectively made Ascii Shading Art. Sadly, it was Too Good to Last, and it's not even available by URL anymore.
 * There also was a cat peeking through the video processing icon. See it here.
 * For 2011, Youtube has a "1911 mode", where the videos are in sepia while music plays over the audio.
 * For 2012, Youtube brings out "The Youtube Collection", where you can purchase Youtube in its entirety, packaged and shipped to you in a convenient 100,000-disc collection!
 * For one April Fool's Day prank, Deviant ART replaced the avatars of all users with an animated gif of Mudkip with the words "So I herd you liek Mudkips" (sic), a reference to an internet meme. This led to many people being infuriated at the site's staff members for using such a meme when (at the time) they couldn't do memes as well. To make matters worse, it backfired in Deviant ART's faces because they also featured an artist user whose account name was along the lines of Mudkipz to go along with the gag. Unfortunately they didn't check out said deviant before featuring him, leading to many to click on his gallery and come face first in very suggestive loli pics (some of which were porn). They removed the featured deviant and chewed out the offensive imagery, but the damage was done and left many red-faced or shaking their heads in addition to the meme.
 * On April 1st 2010, avatars had been changed to Team Edward, Team Jacob, Team Seeker, or Lady Gaga, with matching signatures (though the Team Seeker signatures reflect only Legend of the Seeker, and not Sword of Truth) Llama badges were also released, which became a huge fad.
 * For April 1st 2011 troll faces appeared on random places throughout the website (ironic, since the site has a very strict "No Trolling" policy).
 * in 2012 cats have taken over DA.
 * Furry art site Fur Affinity also has its share of pranks. For a few years, the search engine was taken down and one year, it was put back up for that day, but people got fooled when they saw that it didn't work at all. One common joke its members play on its watchers is to use a thumbnail (preview) of a piece of art they claimed to have made and when people click it, the art is something totally different (example: a thumbnail promises fat fur art and instead, users get an anorexic fur). Usually most members that are aware of the jokes and what the artists usually make usually won't fall for it. Another common joke is an artist making a journal claiming they are going to leave the site forever.
 * The Wizards of the Coast message board has had some good ones. One instance that sticks out is having everyone's avatar switched with one of the My Little Pony pictures. It quickly got out of hand when people who linked to their wizards avatars on other message boards saw the change, and thought the Wiz_0's(mods) were following them.
 * They also once announced a Mattel merger between My Little Pony and Dungeons and Dragons. The pink beholder graphic with bows on its eyestalks remains iconic...
 * The Backloggery saw how far you can take Cash Cow Franchises to on 2009 by randomly adding suffixes and prefixes of popular video game series, shovelware franchises, Super Title 64 Advance and other generic stuff on games' names as you refresh the pages, leading to some utterly ridiculous ideas like Imagine: Resident Evil 5? Superman 64 HD Remix, the redundant Street Fighter Alpha Anthology vs. Capcom, Tom Clancy's Sonic the Hedgehog, and Guitar Hero: Saya no Uta Edition.
 * I-Mockery releases joke games on April Fool's. In 2008, it was a Pickleman (the site's mascot/creator's alter-ego) game, which was really just E.T. with Pickleman coming after you and killing you. For 2009, it's Tetris for Charity, where if you get to the 3rd level, $1 is donated to charity. Halfway through the second level, all the blocks are replaced by random NES sprites, which makes the game impossible. For 2010, it's Pitfall 2010, which looks like the original at first glance,
 * Ambrosia Software released a free program called Screen Cleaner Pro, which claimed to be able to fix up monitors by brightening them; you opened the program, waited a few minutes while it "calibrated", and then the monitor would brighten significantly. Apparently a miracle product...except what it really did was gradually darken the screen, then turn it back to the original brightness. They even went so far as to get a fake positive review from a software site to make it look legitimate.
 * Tales of MU posted an update in 2009, announcing production plans for a Syfy channel spin-off TV show, of which the author claimed pride but apparently had little creative control, resulting in significant deviations from the core themes of the novel. It linked to the writer's Livejournal crossposting, where comments revealed the prank. A few commenters disbelieved the announcement because it referenced "the newly branded Syfy channel" at the end, and were double-pranked to discover Sci Fi's renaming on April 1st, though it was widely known earlier.
 * The Defictionalized Digibutter.nerr once claimed to be bought out by 4Kids. Every forum but the Party, Off Topic and RP forums were locked, and people took on parody alts that made fun of various characterizations and dubbing errors.
 * And a year later, they changed their name to the "Bitlands" (a spin-off site from it already exists) for April 1, 2010. Then it was revealed that there WILL be a name change and it MIGHT be the Bitlands anyways.
 * Unskippable: As a preemptive April Fools' Day joke, Graham and Paul's March 30, 2010 video promised to riff on Final Fantasy XIII, and instead featured  Final Fantasy VI  "Final Fantasy III". "How much difference can one X make?"
 * Google almost always has a yearly joke to pull, ranging from lunar research bases to intelligence-boosting energy drinks.
 * In 2010, Google put up a link to a new "Google Animal Translate" feature.
 * And changed its name to Topeka.com in response to the city changing its name to Google, Kansas. Details here.
 * And now, Google Maps 8-bit for the NES. The video itself shows its work by showing that it is for the Famicom, which had networking features the Nintendo Entertainment System didn't.
 * MuggleNet posts absurd news items on April 1st, such as claiming Scholastic would rerelease the books with titles like "Harry Potter and A Super Cool Stone", "Harry Potter and A Super SUPER Secret", "Harry Potter and A Bad Guy Who's Actually Okay", "Harry Potter and FIREEEEEEEEE!", "Harry Potter and A Super Secret House shhh", "Harry Potter and A Prince, Like The One You Know", and "Harry Potter and A Good Versus Evil Fight". One year they joined forces with The Leaky Cauldron by claiming that the two webmasters Emerson and Melissa (who were already being shipped as "Memerson") had gotten married and were combining sites.
 * In 2010, the fanfic Paradise In Death rickrolled readers. In text form.
 * In 2010, Aeon Genesis finally released their translation of Tactics Ogre.
 * JayIsGames.com created their own Spot the Difference game that leads into an impossible level. The walkthrough included claims that this was a turning point that leads the game into becoming a Deconstruction Game, but in truth, nothing happens at all if you wait, not even a Screamer Prank.
 * In 2011, they reviewed a tic-tac-toe game far too seriously.
 * In 2007 they reviewed a supposedly massive browser game that was actually just a loading screen that never ended. After April Fool's they turned it into an actual review of the downloadable game it was based on.
 * In 2009, they had an overblown review of a game called "Quest for the Crown".
 * In 2012, they created a genuine, playable Text Adventure game, the joke being its completely ridiculous premise. Jay Is Ponies!
 * 4Chan once added a /fur/ channel on April 1st. The userbase was shocked to see it still up on April 2nd. Then they were infuriated when it was still up on April 3rd. The April Fur's Day prank is today considered one of the better things the staff have done.
 * This prank is such a legendary cornerstone of the 4chan community that, when moot added a /mlp/ board to stem the sheer number of pony threads on /co/, it was immediately assumed by the majority of the users that the staff were up to their old tricks with an early April Fools prank. It got so accepted as fact that moot had to top the board with a sticky thread specifically debunking the rumor, not that that stopped anyone from still claiming it to be true up until April Fools Day itself.
 * Neopets has done this for over 10 years:
 * 2000: A page filled with pets that didn't quite make the cut. (The artists were having a bad day.)
 * 2001: An announcement that some of the pets would be redesigned.
 * 2002: The Pant Devil stole everyone's items, including ones in their Safety Deposit Boxes.
 * 2003: A sneak preview of the site's Totally Radical makeover, Neopetz.
 * 2004: A new TCG expansion pack, "Quiguki Armageddon". It featured a parody of their Usuki toys, called Quigukis (based off of the frog-like Quiggles). The Quigukis underwent Defictionalization, everything else did not.
 * 2005: 50 new Neopets, with the announcement that the maximum number of pets an account could have was now 10 (instead of 4). A poll was held, and the most popular (the Lamameeah) was released as an actual Neopet (the Gnorbu), while a few others were released as Petpets.
 * 2006: To stabilize the Neopian economy, NeoCharge was introduced, which taxed users for each page they visited. Failure to pay debts would supposedly result in accounts being flagged, and actions being taken to "compensate".
 * 2007: The Battledome was closed, as well as the Battledome section of the forums, and any weapon shop.
 * 2008: The NeoBuddy system was introduced, where a questionnaire would match you up with a buddy (Bug Eye McGee for most, Sir Fufon Lui for a few), who would pop up from time to time and give advice.
 * 2009: It was announced that the pets would be phased out in favor of Neoplants, and there were minor jokes around the site as well:
 * The Hidden Tower was closed until further notice, as was the Faerieland Employment Agency.
 * The Tiki Tack Tomobola was perpetually out of money, and kept asking for a 1 NP donation.
 * Neopoint inflation rose tenfold, and interest rates at the Bank were lowered (the Banker got a new appearance, as well).
 * The Stock Market was stuck; no prices moved up or down.
 * 2010: More minor jokes:
 * The Battledome: In 3D!
 * The Prank Warehouse opened up, which allowed users to send various pranks (such as pies or slime) to their friends.
 * Neoboard filters were added—for instance, "3.14" would be changed to "numbers", "snot" would be filtered into "faerie dust", and "slime" would be changed into "Twilight"
 * They also snuck one into their Facebook page, with some concept art—of the "Meat Faerie".
 * In one of the most cruel examples imaginable that one porn site enacted an April Fool's joke resulting in the ban of all lolicon/shota artwork from the site. What makes this particularly nasty is the joke was cooked up in response to e-hentai's ACTUAL ban of all underaged artwork due to Moral Guardian antagonization of their advertisers, and used the subpoena sent to them as the excuse, doctored up to look like it was sent to said pornsite instead. The joke was meant to be incredibly obvious, as the featured image was Rugrats (with, at one point, a feature change to Popeye dressed as Sailor Moon in response to an anonymous commenter along with the comment 'But older characters cosplaying as underaged? Yes that's still acceptable.'), however due to the e-hentai debacle, users just couldn't believe it was a joke and some serious debate went down over the state of the world and continuing persecution of lolicons. Some artists even ragequit over what they took to be impending censorship of their art on a site that shouldn't have it. All staff were told to keep up appearances for a day after, duplicate pics that were to be deleted were saved up for about a week prior, then commented upon before being deleted to lend to the authenticity. A few artists still haven't returned, and probably never will.
 * SydLexia.com posted the 100 Best Virtual Boy Games Ever. It's obvious that the overall number of Virtual Boy games is nowhere near that number. Virtual Boy Wario Land was the only game listed, and in all 100 spots too, no exceptions. Reading the commentaries, they seem to claim that there are many versions of Virtual Boy Wario Land, even versions for different consoles, all with the same title. Some of the comments were ripped directly from the prior Top 100 lists Syd had made. There were even surprise comments from Jareth The Goblin King and Avril Lavigne.
 * On podcast All Movie Talk, in the intro portion for the last Tuesday before April Fools' Day:
 * Sam told listeners that the episode contained the word "movie" more times than any other episode, and encouraged listeners to verify this (true or no, that's a lot of time to be counting the word "movie");
 * Stephen claimed to have gotten everyone a gift...only to reveal that it was a free movie podcast (just like every week);
 * Sam listed off the segments for the episode (which were, of course, totally false);
 * and finally, they introduced themselves as each other.
 * Wing Commander CIC, a Wing Commander online fandom news site, changes the main site's look to something silly on April 1st, and posts "news" articles that are loaded with take thats, at themselves and others, often along with joke announcements of fictional new WC releases.
 * GameFAQs always gets in on the April Fools Day craze as well. In recent years it's been toned down, sometimes with the only gag being a silly Poll of the Day and maybe the creation of a few joke message boards. But in the past, they've done some huge things, including:
 * Banning the latter "e"
 * Changing the entire layout to create GameFAX, a site all about the Xbox.
 * Promoting random users to moderator status (though obviously not giving them actual power)
 * Putting up a fake notice on the homepage about the site being shut down for illegal activities
 * Removing all usernames in an effort to stop harassment
 * TASvideos publishes joke runs during April fool's day. For an example, a speedrun for Color a Dinosaur or Desert Bus.
 * From 2005 to 2009, VGMaps.com: The Video Game Atlas used to feature maps for fake video games. In order, these are The Legend Of Zelda: Link's Awakening Advance, Mega Man Solid X: Guns Of The Mavericks (solid-x.com links dead), Super Kid Icarus, The Legend Of Zelda: Oracle Of Hours, and Metroid Dread.
 * Ponibooru (a Danbooru-like website for My Little Pony Friendship Is Magic) became overrun by Pinkie Pies during April Fools' 2012.
 * Equestria Daily, a popular blog/news-site for the My Little Pony Friendship Is Magic fandom, converted the website from Generation 4 (Friendship Is Magic) to Generations 1-3.5 (the original My Little Pony to the Tastes Like Diabetes, oddly-bulbous-bodied characters from the series immediately before Fi M.)
 * The B-movie review site Stomp Tokyo reviewed nonexistent movies on 1 April. The first of these was The Dellon Godhead, a Doctor Who / The New Avengers crossover, supposedly including Brian Blessed as a football-obsessed Blackbeard.

Newspaper Comics

 * In 1997, several comic artists swapped strips, producing such oddities as a Dilbert comic in the style of Family Circus (which Dilbert author Scott Adams described as one of the signs of the Apocalypse).
 * Kevin Fagan was unable to find another cartoonist to trade Drabble with, so he drew it with his left hand.
 * In 2005, several comics including FoxTrot, Pearls Before Swine, and Get Fuzzy, did identical comics where one character plays with a Ouija Board and uses it as an excuse to hit another, eliciting the response "Somehow I imagined the afterlife to be a more peaceful place."

Tabletop Games

 * Dragon Magazine, the house organ for Dungeons & Dragons, would usually dedicate their April issues to sillier fare. For example:
 * One issue had a series of mixed up spells like 'Find Terrain' for which the 'somatic' component was to fall forward, at which you have just 'found the terrain'.
 * Another issue had on its cover a chubby warrior holding flowers up to a beholder which had on makeup and flowers..."Beauty is in the eye of the...Oh nevermind!"
 * Another time, they packaged the April Fools material in one section of the magazine, with a cover page that parodied the heroes-steal-giant-demon-statue-eyes cover of the 1E Player's Handbook. Exact same scene, except the demonic statue and gem thieves are all teddy bears.
 * A few years ago, shortly after 3.5 introduced a Flaws mechanic, they did flaws for Commoners (the least powerful of the NPC classes), one of the flaws called "You Got Chickens" had the character suffering a 50% chance of retrieving a chicken any time they tried to draw something from their pack. This was promptly exploited on the Character Optimization board.
 * Who could forget the parody songs of "Bard On The Run"?
 * White Wolf published the supplement Dudes of Legend on April Fool's day. A very NSFW Take That filled supplement with rules for, among other things, using glitter to let vampires go out in the sun, and gaining superpowers from homoeroticism.
 * On April Fools Day 2009 they released the Scroll of Swallowed Darkness, an incomplete, sex-themed supplement for Exalted. On April Fools Day 2012, they released errata for it.
 * Palladium Books has a combination fanzine/sourcebook for Rifts and other Palladium titles called The Rifter. The created an April Fool's Issue called The Rifter 9 1/2, which was full of ridiculous characters, alternate rules, and other silly content. A Running Gag throughout the issue was that Palladium Books had been sold to the fictional Percy Ferkleberger, who began effecting massive changes in Rifts. The most notable example was the new rules for "Giga-Damage," which was a massive in-joke regarding the game's love of More Dakka, the fact that Rifts tends to attract Munchkins, and Power Creep, Power Seep in general. Most amusingly, the Rifter 9 1/2 was made primarily as an April Fool's Joke on The Rifter's editor, who had heard nothing about it until the first copies arrived at the warehouse.

Toys

 * Bionicle Sector 01, the Bionicle Wiki, Lost quite a few of their images and pages a while ago, but managed to find some replacement images of the Toa Nuva, Mata Nui, and Makuta Teridax, thanks to a certain Derpy Hooves...

Video Games

 * In possibly one of the most elaborate April Fools' Day schemes ever, IGN.com spent six months filming the trailer for a live action Zelda film. The trailer was hit or miss with the fans; some were ecstatic that the movie was being made, others were horrified at the idea. In any case, an impressive amount of detail went into the making, complete with CGI monsters, music taken from the games, and a complex storyline expressed in three short minutes of filming. The only clue to its status as a hoax was the purported release date for the actual movie—April 1, 2009. At one minute after midnight on April 2, 2008, the site admitted it was a fake, and released their making-of featurette, which is longer than the trailer itself.
 * It appears that in 2009, they announced the release of a "hardcore" expansion of Super Smash Bros. Brawl that apparently differed little from the regular version except for the addition of decapitation and gratuitous blood and gore.
 * In 2010, IGN made another fake movie trailer for Halo...  FINISH THE FIGHT!
 * In 2011, instead of focusing on video games, IGN parodied Harry Potter and the Darker and Edgier milieu of cable television with a trailer for a fake TV show called The Aurors, made by The Shield's Shawn Ryan and airing on FX. It was also to come with an M-rated video game adaptation.
 * 2012 had a trailer for a Saturday Morning Cartoon Band Toon adaptation of Mass Effect, animated by Harry Partridge. "Mass Effect, tune up!"
 * Blizzard Entertainment has a tradition of April Fool's jokes which runs back at least to the development of Warcraft III, when they famously announced a race of panda-people as the fourth playable faction (who are going to be an actual, playable race in an upcoming WoW expansion). In recent years, the jokes have been getting bigger:
 * 2006: They announced the Two-headed Ogre. The ridiculously complex rules for playing such a creature (you literally had to play with a second person on a second account, randomly assigned) made it obvious it was a joke.
 * In a slight subversion, they also announced a new neutral hero, the Goblin Tinker, for Warcraft III on the same day that was not a joke. They tried to make it seem like either of the two could be real but it was fairly obvious.
 * 2007: They announced Burgercraft: A chain of fast food restaurants that would serve Blizzard gamed themed food. They also announced the new Alliance race would be the Wisp, the weakest member of the Night Elf army, who could only attack by self-detonating. Finally, a "fired" employee "leaked" the next patch notes, a list of facetious changes ranging from game breaking (Druids may only shapeshift outside of dungeons) to absurd (Hunter pets have a small chance to attack their owner when hungry).
 * 2008: Due to Blizzard's parent company purchasing Activision and changing its name from Vivendi to "Activision Blizzard", Blizzard announced a "second prestige" class: the Bard, which required you to play Guitar Hero while playing World of Warcraft. Also, poking fun at Sony's attempt to turn their MMO EverQuest into a Warcraft style RTS, Blizzard announced that they were releasing "WoW: Heroes of Azeroth", an RTS prequal to World of Warcraft. It was literally Warcraft III, and also served to poke fun at WoW players who were unaware of the previous games and lore. There was also the announcement of the "Tauren Moorines" for StarCraft II.
 * 2009: Blizzard announced a dance battle system complete with trailer. The controls were said to work like riding a vehicle in Wrath of the Lich King. For StarCraft II, there was the announcement of Terratron, a Humongous Mecha Combining Mecha made out of Terran buildings. For Diablo III, the Archivist was announced as a new class, basically having the character play a Deckard Cain-like old geezer whose dialogues are pretty much senile rantings. And on the UK World of Warcraft site, they announced a "Pimp My Mount" feature, which allows players to add ridiculous customizations to their mounts a la Pimp My Ride. Additionally, every post made of the World of Warcraft forums that day was peppered with random roleplaying lines.
 * 2010: Blizzard announced a new character rating for World of Warcraft called the Equipment Potency EquivalencE Number a vertical bar on your character that grows as their gear improves (a Take That at players who rely too much on gear ratings to determine their worth), and the Battle.net Neural Interface which permanently immerses the player in full VR and hopefully doesn't cause any permanent brain damage. And the WoW Armory character feeds had all boss kills changed to " Cheesed Boss" and all loot changed to " Ninjaed [Item]". Blizzard also introduced the new Battle.net matchmaker, a dating site where players would find romance in the form of "Someone to pwn noobs with." They also announced Diablo III blankets and pillows and a Deckard Cain GPS voice pack to go with it.
 * 2011: Blizzard announces Crabby, an expy of Microsoft's Clippy, to assist on the forums and in-game for World of Warcraft. For StarCraft II, Blizzard makes a return to consoles, with peculiar motion-sensor tech. In addition to this, there are spoof patch notes for SC2 and WoW, which serve as playful take thats to player complaints concerning both game balance ("Fixed a bug where Terran players were able to lose a game.") and aesthetic concerns (Every class with fire-based abilities gets green fire - except Warlocks).
 * 2012: Blizzard will evidently be producing: Educational games for children such as "Zergling Teaches Typing" and "The Westfall Trail"; A mobile game, "Supply Depot 2: Combat Elevated", about the exciting Starcraft metagame of raising and lowering Terran supply depots, with features such as color-coded endings and lots of unlockable hats; Plastic toys to replace the authenticator, called Zergotchi, who grow and require periodic feeding to continue supplying authentication codes; A line of teen-oriented literature set in Blizzard universes and inspired by The Twilight Saga, The Hunger Games, et cetera; It's noteworthy that for the past several months they had been accused of dumbing down WoW with concepts from Pokémon and FarmVille. Also, Crabby returned with randomly generated hats.
 * The 1998 Textfire Hoax produced a collection of playable text adventure demos (including Coma! An Interactive Action Thriller and Flowers for Algernon and "Operation" adaptations) that represented the ostensible catalog of a commercial Interactive Fiction studio.
 * Steam once did an April Fools' Day gag by releasing fake patch notes for Counter-Strike: Source that started with features such as "cost of sniper rifle reduced by 50%", "de_dust map removed" and "jumping now increases travel speed by 50%" and got progressively more ridiculous.
 * Many people celebrate April Fool's in a funny and aggravating fashion in the Pokémon fandom. Including the creators (Gamefreak).
 * Now Serebii is claiming they don't like misleading the public, undoubtedly setup for THEIR jokes.
 * Probably the best one was releasing the rest of the English Diamond and Pearl data in one fell swoop after trickling it out bit by bit. Making us think it was fake was the joke in itself: The names were real.
 * Now take another look at those "new Pokémon" from 2005. As of Generation IV, there really is a pre-evolution of Chansey, and also a Pokémon that looks a lot like "Korechu" (Shinx). April Fools' Day joke, or stealth preview? (And remember, the fabled "Pikablu" turned out to be Marill, so...)
 * For 2011, Bulbagarden changes its name to "Fushigarden" (Fushigidane, the Japanese name for Bulbasaur) and acts like it was 1998, when Pokémon was still young.
 * The day before April Fools' Day 2009, the developers of the Super Mario Bros.. fangame Mushroom Kingdom Fusion released this video.
 * The video is private now, it was a video showing gameplay of a "new character", Mickey Mouse.
 * Harmonix appears to release ridiculously silly (and not at all rock-like) songs for Rock Band during the week of April Fools' Day. In 2008, it was Still Alive, available for free download. In 2009, three songs from SpongeBob SquarePants were released to be sold at a cheaper price than the average song.
 * A tradition broken in 2010, when instead they opted to release an entire Jimi Hendrix album.
 * In 2012, they announced a board game.
 * Furcadia has released a number of pranks on April Fools' Day. One prank flipped upside-down and reversed the player's view window of the world on main maps, so navigating was extremely difficult. Another, recurring in some form each year, is a global text filter—one year, all curse words (and the word 'yiff') were filtered to "NARF". Another year, parodying thesaurus-rape roleplay common on some areas of Furcadia, the word 'eye' or 'eyes' would be filtered to 'orb' or 'oculars'. More recently, April Fool's pranks have revolved around avatars, in an effort to gain funding for the graphics update; in 2009 there was the Toasterwing event, turning everyone on a main map into a flying toaster; in 2010 there were two localspecies who you would become when one ran into you, the Fluffs and Floofs, and a massive zombie apocalypse battle took place.
 * Gaia Online has a history of pranking its users on April Fools' Day, often by finding creative ways to blow their heads up.
 * In 2004, strange gift boxes appeared randomly around the main site. Users who clicked on them had their faces covered in soot until they changed outfits. "Sootfaces" eventually became a reason not to change your avatar, until the great avatar resave wiped them out.
 * In 2005, resident megalomaniac Johnny Gambino built a giant tower. He was assassinated, and the tower fell on top of the mansion of his rivals, The Von Helsons. (They all got better)
 * In 2006, resident Mad Scientist Labtech X made Gino Gambino explode in a Sphere of Destruction that apparently destroyed all of Gaia. No one was killed. (Johnny K. Gambino actually came back to life!) But the explosion did attract a bunch of aliens
 * In 2007, Gaia did a repeat of its classic 2004 joke, with boxes that apparently gave out Platinum Halos. (The Angelic Halo is one of the most expensive items on Gaia, and a silver version had long been requested). Equipping it gave you a classic "Sootface".
 * In 2008, The Easter Bunny (who happens to be a cyborg. Don't ask), angry that its holiday was being neglected, gave out Easter Eggs. When April 1st rolled around, users were asked to open their eggs...KABOOM! They also released a special pair of pants that could be worn as a multitude of different things...except, ironically, pants. (That pose was added in on the second)
 * In 2009, in response to complaints about Gaia accepting sponsorships and "selling out", Gaia created its most elaborate prank yet. The logo was altered to read "OMNIDRINK", with a tiny "presents Gaia Online" in the corner. A video on the main page implied that Gaia had been forcibly bought out by a Mega Corp, that made products you were not supposed to drink. (Including a hilarious "Personal Improvement Spray", that apparently made you more manly). Players who visited the information page would see multiple messages asking them NOT TO DRINK OMNIDRINK PRODUCTS, and would be given a free sample of "Personal Improvement Spray", with a "CHUG IT!" option. The results aren't pretty.
 * The Gag carried over to zOMG!, Gaia's MMO. Player's logging in will find that Omnidrink has redecorated Barton Town, and that a new Expansion Pack World (Based off both Greek and Aztec Mythology) has been added in. Players get a chance to board an Airship that will take them to this new world, but find that it simply takes them to a fake loading screen, parodying zOMG's infamous loading issues from earlier builds. Upon returning to Barton Town, players received an equipable error message.
 * users began playing along with the zOMG! prank, by discussing the new world at length and explaining to those fooled that the airship had crashed because it was attacked by an Air Shark (made slightly more believable by the presence of a Landshark in the beach area). The Air Shark was later homage by an evolving item's pose.
 * The forums played along with the joke as well, and began a war between those who had been brainwashed by OMNIDRINK, and the resistance.
 * In 2010 Gaians signed on to find a swf image with a video repeating "Loading..." over and over. On the left of the image was a button to be clicked, this button led to a 404 SUSHI ERROR page. Later, users were able to gain an item called "Phoenix Up" from the fake 404 page ...which later turned into a sootface, as well as a bonus pose of a Grunny . They also added several blaring banner ads, some that even covered up avatar editing and trades. As of now there's no proof they were connected, but it ended up backfiring, and the developers fixed it.
 * Also, Dernier* Cri  returned with a single item that cost 300 million gold and was only about a few pixels wide. The description says that it was made for "commemorating a very special day", which shows that Brennivin is at least in on the joke.
 * In 2011, Gaia decided to do Something Completely Different. Mike Sego stepped up for the job of replacement CEO after Craig decided to step down to pursue his own interests. When word got around that Mike had worked for Facebook in the past, there were considerable fears and doubts within the userbase concerning how he'd handle the site, eventually morphing into rumors that Facebook had in some manner acquired Gaia and was ruining the site. So much like Omnidrink, the staff relieased the Meowbook event as a response to the rumors. The forum posts all showed people with a few randomly chosen cat head clippings imposed over their avatar's head, emotes all recived a visual overhaul to give them cat ears, even the shop keepers were given cat heads. A Premium Cat Feast item could be claimed over the entire weekend by clicking the "brought to you by Meowbook" banner underneath the regular Gaia logo and clicking the submit button on the fake Meowbook signup page.
 * Command & Conquer: Red Alert 3 has a freaking Mammoth Tank on 2009, which is essentially living mammoths outfitted for war. Though this didn't work terribly well, considering how silly the game already was (War bears, anyone?).
 * Every year, some gaming magazine/website or another announced that Nintendo and Camelot were finally making Golden Sun 3...then it was actually announced at E3 2009, which was sadly nowhere near April 1.
 * Not even Aya Reiko Touhou is safe from this. On March 31st, 2008, a false trailer for a spinoff RPG was released. The fact that the trailer was basically a hack of Valkyrie Profile's engine, along with having very professional-looking graphics and remix of an official Touhou track, just made the revelation that it was all a lie and this amazing-looking game would never ever be playable hit even harder.
 * Kingdom of Loathing has done a joke each year since 2005.
 * In 2008, the Puzzle Pirates staff "accidentally" allowed everybody to read a (fake) staff-only forum, which was filled with posts like "Bug report: My 'send instakill' button is grayed out."
 * In 2000, Cyan announced Myst Mayhem, Myst turned into a First-Person Shooter game. The gun-turret tower and foreground gun did appear as Easter Eggs in real!Myst.
 * LittleBigPlanet (Play Station 3-only) had free "Hessian Sackboy Fragrances" DLC for a limited time (one week from from April 1, 2010). They're simply extra hand animations.
 * BlazBlue versus Arcana Heart. This was found on Arcsys's website.
 * Which became (more) Hilarious in Hindsight when Platinum The Trinity was announced for BlazBlue: Continuum Shift DLC.
 * And when Arcsys announced they would port Arcana Heart 3 to console.
 * And even more when Mikako Takahashi (Heart Aino's seiyuu) guest stars into BlazBlue's official radio show 'Bururaji' and rechristened it for one episode 'Araraji'. Complete with BlazBlue chibi style sprite for Heart (they did it with Sol already...)
 * RuneScape has done several. In 2004, they announced that a cowboy-like merchant named Diango was selling Horses, which players had wanted to see in the game for a while. He was selling Horses- toy horsies.
 * Diango was later re-used in the 2005 and 2008 jokes, where two more popularly demanded items, dragon platebodies and dragon kite shields, usually abbreviated to "Dragon Plate" and "Dragon Kite" respectively, were sold. They were, of course, actual plates with a dragon on them, and kites with a dragon on them that could be flown. These joke items remained in the game after April Fools' Day, although re-named to make the fact that they were jokes more obvious. Dragon Platebodies were actually added to the game later.
 * Their 2007 joke was a fake newsletter on the front page claiming a lot of silly cabbage-related updates were going to be released that month, with an actual newsletter being released the following day.
 * In 2009, they did something else cabbage related by making cabbages wieldable, and gave the ability to make some of the cabbages in the game able to move on their own and be kicked- with the secret joke that if you kicked one from Falador to Oo'glog (Which takes a really long time), the Cabbage King, Brassica Prime (mentioned in the 2007 joke) would show up and congratulate you.
 * In 2010, they announced that they were making a RuneScape theme park in England. It was an obvious joke, but some people thought it was real anyway until they revealed it was a joke the following day.
 * Some versions of Football Manager have an Easter Egg / April Fools gag that shows up only when both the in-game date and the actual date is April 1st.
 * Every April 1, Bungie releases new information about Pimps at Sea, which apparently has the most advanced and complex economy in a game, ever.
 * League of Legends has dabbled in this a few times, back in 2009, they announced Urf, the Manatee. A Manatee who uses a Spatula and a Chicken foot, but it was quickly revealed to be a joke. The NEXT year they did it again, but made it look much more official, but again, didn't come full circle. They actually had a STORY for the second joke, another champion had killed and skinned the poor manatee. (Said champion then got the skin of the flayed manatee as an in-game skin) At least the second time, all the money spent on the skin went towards real-life Manatee Preservation Groups.
 * In 2011, they posted a set of patch notes that would either be ridiculous in a game balance method, uses Memetic Mutation, or are otherwise pointless changes to make a joke on an aspect of the characters being 'changed'.
 * Minecraft had an in-game Take That at Team Fortress 2's crate system for April Fools 2011.
 * Unfairly OddParents is an April Fools joke, composed primarily of unfair Trial and Error Gameplay.
 * An example that very rapidly became Hilarious in Hindsight: in 2006, Gamespot did an April Fools' article predicting the triumph of the console then known as the Nintendo Revolution in the next Console Wars on the strength of its low price (for both the console and its games), its library of classic, inexpensive downloadable titles, and its ability to tap into markets that aren't thought of as "core gamers". Did we mention that this was meant to be an April Fools' joke?
 * The teams of two indie fighting games produced fake screenshots for supposed retro handheld versions of their series in 2012: Skullgirls had Skullgals for the Neo Geo Pocket Color, and the familiar puke-green classic Game Boy colors found their way to the supposed DSiWare "Nettou Battle High".
 * Operation Rainfall, an online campaign famous for getting the Wii games Xenoblade Chronicles and The Last Story to the United States, announced that they would add another game to the campaign: Love Plus, a rather notorious Dating Sim that is otherwise known as "that one game where somebody married one of the characters in real life, ceremony and all." Considering the series's reputation, most people smelt a rat, and some wondered if they were being suicidal, since they've built up a reputation as crusaders against No Export for You. And sure enough, it was a joke.
 * TYPE-MOON has a penchant to do quite elaborate pranks on their website for Fool's day, usually using his proprieties on some outrageous new premise. To date:
 * 2005: Neco-ARC: the Movie, a film starring everybody favorite Joke Character from Melty Blood.
 * 2006: Hazakura Romantic, a seemingly original BL novel concept (co-opted with Nitro Plus) that left many people wishing for their Defictionalization.
 * 2008: Type Moon as a girl wrestling promotion!
 * 2009: moon.cinemas.jp, a site imitating a typical movie theater chain front page, where all the movies were parodies of well known films strarred by their characters (up to including a parody of Densha Otoko starring Weaver Velvet and Fate/Zero!Rider that was revived as the April Fools joke for ufotable in 2012). Hilarious in Hindsight because one of the "movies" announced, one based in the (then book only) epilogue for the movie series of Kara no Kyoukai, was eventually done and released for real.
 * 2010: Rather than fully changing the main page as in former years, Twitter- sorry, TMitter feeds were added to the site. Hilarious and very in character Twitter feeds from their most popular characters. This will keep featuring on the following years in addition with whatever joke they play in said year.
 * 2011: Instead of a typical joke/parody, for their main page they released a serious short story about the very concept of April Fools, titled "The Room of the April Witch". For their mobile site, on the other side, they reprogrammed it to show a different (parodic) image and accompanying text with each reload.
 * 2012: Koha-ACE, a poster for a movie parodying Gundam AGE. The accompanying texts did a self-deprecation number on their constant delays on Mahou Tsukai No Yoru's release, through.
 * 2013: Back Alley Satsuki - Chapter Heroine Sanctuary, a hilarious parody of Saint Seiya: Sanctuary Chapter, with new episodes being released during the day. Featuring a lot of characters from their lesser known franchises, and even a character from a light novel written by a member of the staff of the eternally unreleased then-visual-novel-now-anime Girls' Work.
 * 2014: TM-channel, a series of Nico Nico Douga-like "streams" of several characters, some of them done in a vlog style.
 * 2015: A triple combo: the "release" of a new character for the capsule minigame in the PlayStation Vita version of Fate/hollow ataraxia, a Pokemon-style championship on said game (complete with A-tuborudo and The Big Ben Company branding), and "Imperial Roma", a talent agency launching the idol careers of several characters (Nero being the main spotlight), complete with release dates and everything. The TMitter this year turns to be a particularly elaborate one, with 28 accounts running at the same time in the same storyline.
 * 2016: all the illustrations of the main page had been replaced by ones on the same style of KOHA-ACE and other comedic parodies. Also the news has become more comedic ones, under the concept that the site has been invaded by the characters of their mobile game Fate/Grand Order.
 * There is also Fake/states night, a joke spinoff concept written by Ryohgo Narita of all people as a April Fools for his own site. Later released as Fate/strange fake in the official TYPE-MOON magazine.

Web Animation

 * The Asdfmovie series has a possible example: two days before April Fools' Day 2011, creator TomSka and animator RageNineteen responded to fan ZxHeiserxZ's request "Make an ASDF film/movie for like 20 mins or so :D" by making the Stylistic Suck-filled THE TWENTY MINUTE ASDFMOVIE in 20 minutes.
 * Homestar Runner has done a few April Fools' Jokes.
 * In 2003, homestarrunner.com became kingoftown.com, complete with a new intro and main page featuring the not-at-all-popular incompetent ruler of Free Country, USA. ("King of Town! Hooray!")
 * In 2004, the site was replaced with a bogus domain registration site from the fictional Thorax Corporation...which was actually a flash cartoon where Stinkoman showed up to fight a animated GIF of a shovel-wielding stick figure. ("Hey, Stickly Man, whaaaat are you doing?")
 * In 2005, the site was replaced with a (fake) main page for a subscription service, HomestarRunner.com Pay PLUS!
 * In 2006, all the cartoons and main pages on the site were flipped upside-down. This caused some problems with Action Script on the site, and, to two tropers' dismay, the Strong Bad Email "Virus".
 * In 2009, the Monday before had featured a cartoon called "Sbemailiarized Entertainment", in which after a long lack of Strong Bad E-mails, Strong Bad decided there wasn't really a big difference between sbemails and other cartoons, and he could just stick himself answering an e-mail at the beginning and end of any old cartoon and it would work. After a very long prank hiatus, the day itself had the intro movie replaced by a Sbemailiarized version.
 * In 2010, the site's intro was suddenly replaced with HSR Xeriouxly Forxe, a parody of Darker and Edgier.
 * Episode 17 of Making Fiends was released on April Fools' Day. Absolutely nothing was strange about it. Well, besides the fact that every dialogue was spoken in Bulgarian. A subbed version was later released...in Intentional Engrish for Funny.
 * In 2008, Alvin Earthworm made an animation of the head from Mario Teaches Typing 2 giving a Rickroll. See it here.
 * In 2009, he redid a fight scene from the most recent episode, but with all the characters' sprites replaced by images of Sprite cans. In addition, the background was replaced with sausage packs.
 * In 2010...Nah, it's too weird for a description. Just watch.

Webcomics

 * In late March 2006, the Chris Hastings and Kent Archer of The Adventures of Dr. McNinja posted on the site news that they thought they were being stalked by ninjas. On April 1, this was followed up by a post in which the ninjas killed Hastings and Archer, then imitated them and announced the end of the comic.
 * In 2008, they put up this comic, which was only slightly odder than the comic's usual fare.
 * In 2009 they began a new campaign of in-strip product placement, while on the newly fan-run forums a campaign of McNinja-themed word filtering of random phrases was enacted.
 * The Book of Biff did this at least twice. In both instances, an established element of the comic is rendered differently and the author blocks out any comments pointing these out. The very next day he unblocks the comments, posts the non-joke version of the same comic, and moves the joke comic to a different page.
 * In 2008, Biff's face looks normal.
 * In 2009, Biff speaks!
 * In 2009, Brawl in the Family was briefly replaced with the rather bizarre Waluigi in the Family, or WiTF, starring Waluigi. It updated 17 times over the course of the day. The eight-digit strip numbers were a nice touch.
 * In 2010, the front page was adorned with a "letter from Nintendo" ordering the comic to shut down. It listed the comics that Nintendo had issue with, and their offenses. Underneath the letter, there were also new Waluigi in the Family comics.
 * In 2011, the comic was called "Philips' Box", with its jokes based on the CD-i games. The main story was that Mario hits a box, freeing the spirits of the CD-i games. Over time, King Dedede goes crazy since Kirby, Waddle Dee and Adeline had been possessed by the spirits and wonders what could end their insanity. At that moment, Waluigi comes back from his vacation and scares the spirits away back into the box by taking his clothes off.
 * In 2012, the author was sick, so he wrote a Waluigi apology letter.
 * In 2008, Darths and Droids (which uses images from the Star Wars films) claimed they had received a cease-and-desist letter from Lucasfilm, and would henceforth be making the comic using photographs of themselves re-enacting the films. (Move mouse over the comic image)
 * In 2010 the narrative switched from being a gaming session into a The Princess Bride tribute.
 * In 2010, Kristoph Gavin Ace Attorney did one of these, where a minor character is suddenly revealed to be the true killer, and shoots the protagonist.
 * Queen Of Wands very briefly put up a shot of one of the characters tearfully confessing she was pregnant, to fan concern. Soon after, this was replaced by a different, jokey comic. Later in the Story Arc, the same pregnancy scene was used exactly and unironically. On April 1st.
 * In 2008, Dinosaur Comics, Questionable Content, and xkcd all temporarily stole each other's websites.
 * In 2009, the author of Goblins claimed that the author of Least I Could Do had used one of his characters without permission and that he was suing.
 * In 2008, Gunnerkrigg Court replaced the latest page (at the time) with [[media:gc-aprilfools-385.jpg|this.]]
 * Nature of Nature's Art added a temporary panel one April Fools' Day where, after kills, the corpse gets back up and says, BOO.
 * 2010's April Fool's joke is an elaborate and surprisingly thoughtful comic about a sullen looking man who adopts a Pikachu,, and uses it to win a tournament. It really has to be seen to be believed.
 * 2011 continued the tradition with a comic about a man who creates "the next human brain". It's a bit of a Mind Screw.
 * For 2008, in The Phoenix Requiem, Jonas gets into his TARDIS and vanishes (pictured above).
 * In 2009, Shortpacked! ran this Roomies comic, with the explanation that, since the Shortpacked! storyline had become fundamentally broken, Willis was doing a reboot of the entire Walkyverse.
 * Which is now Hilarious in Hindsight with the coming of Dumbing of Age...
 * In prior years, Willis ran Dinosaur Comics-esque strips, recycling the artwork in subsequent years in Dinosaur Comics fashion.
 * One prank in particular April Fools changed Shortpacked's site layout to that of "Evil Twin" McAwesome's which in fact, introduced them.
 * In 2008, The Wotch celebrated by having Robin abruptly decide, "Oh, who cares if this makes sense or not, I'm doin' it!" and dramatically smooch Cassie. 2009 took a different angle by saying that since Anne (the author) had hurt her arm, which she had, Jason would be taking over the artwork for the next month. It actually went over pretty well, even among those who bought it.
 * El Goonish Shive had not one but two non-canon arcs for April Fools' Day, the first (called April Fool's Week) consisted of odd fillers that featured things like Tedd and Sarah making out, Sarah becoming a Were-Squirrel and the page not actually being drawn one day. The second (known as II slooF lirpA) followed Dan accidentally altering the rules of the dimension, transforming all the characters.
 * The Whiteboard has done an AFD strip since the first one after the strip began, most of them playing on the general theme of Fan Service. In 2009, the author changed the front page to look like a directory listing, including folders for "alternate storylines", a "passwords" text document, and even a well-executed Rickroll. Readers actually called the site's host to warn them of the security hole.
 * In 2010, Xkcd redid its main page to look like a Unix terminal, complete with a command line interface and MUD Shout-Out jokes (type "look", or "go south"). You can still find the terminal here.
 * For 2011, all of XKCD's comics are in 3D. This is also still findable.
 * 2012 brought us a comic which becomes completely different comics on different web browsers or operating systems, and sometimes even changes due to your physical location on Earth. One appeared only to people who signed up to see Randall's talk at CNU.
 * In 2010, Questionable Content updated with a page straight out of Magical Love Gentleman, complete with matching page layout. Glowing crotches are involved.
 * In 2010, Dinosaur Comics replaced the entire cast with Nedroid characters (Reginald in place of T. Rex, Beartato in place of Utahraptor, etc). Not just in the latest page, but in the entire archives.
 * In 2010, Unwinder's Tall Comics changed its name and format to Unwinder's Short Comics.
 * In 2010 the Dresden Codak website was given a Le Film Artistique paintjob by This video.
 * And again in 2012.
 * In 2009, Several characters from Namir Deiter and You Say It First (both drawn and written by the same people) ware swapped for each other, with the dialog for both comics remaining unaltered. In 2010, both comics were drawn with the characters appearing as human.
 * The KAMics in 2005 KAM quit which actually started off a short storyline; in 2009, to wrap up a humorous disagreement between him & the author of Magical Misfits, did this; and in 2010 turned it into an April Fools Month turning his various characters into ponies.
 * While Holiday Wars has never down a special for April Fools' Day, it does include it as a character. It's portrayed as a shapeshifting prankster enslaved to the Easter Bunny.
 * Bittersweet Candy Bowl, "In The End"
 * In 2011, Here Wolf was replaced by the fake comic Stupid Priest.
 * Femmegasm and World of Fizz swapped artists for April Fools Day in 2011.
 * In Impure Blood, the author and the artist traded roles for the strip.
 * In 2011, Beyond the Canopy briefly turned into a parody of Fist of the North Star.
 * In 2002, Eight Bit Theater had Garland destroy the universe.
 * Far Out There pulled the fake "ending" gag in 2009 and again in 2010.
 * 2011's April Fools began a tradition of "debuting" a drastically new style: fist Dada Comics, followed by Sprite Comics in 2012.
 * In 2012, Homestuck did two fake updates that set off the update notifiers without actually adding or changing anything. The actual updates that fell on April 1 involved, so they seemed like jokes—but turned out to be a real plot development.
 * Evil Plan the Webcomic pulls something every year.
 * In 2010, they posted what looked like a repeat update of the last page. It was actually a gif, and after a few seconds, it degenerated into an edited ZALGO mess, complete with blood pouring from the characters' eyes.
 * In 2011, they had an obviously fake link to download a fictional theme song for the comic. Turned out that the link really DID go to a theme song, by Andrew of Songs to Wear Pants To.
 * In 2012, they redesigned the site and did "Planstuck," parodying Homestuck's art style and use of gifs. The artist updated throughout the day based on comments from the readers, finally clocking in at 95 updates.
 * In 2012, The Non-Adventures of Wonderella replaced their homepage with No-Nad Ventures, a company selling fake testicles for neutered pets.
 * In 2012, Cucumber Quest was abruptly retooled as the testosterone-fueled Cuke or Die II: Cuke Harder. (Preserved here.)
 * In 2016, several webcomics decided to pull unanimously the same "extremely unoriginal" joke. Among those in the game were Cyanide & Happiness, Safely Endangered, The Awkward Yeti, Extra Fabulous Comics, and over 40 other webcomics.
 * Nerf Now finally turns into tentacle hentai.
 * Yet Another Fantasy Gamer Comic has "guest comic" (2008), Doctor Who crossover gag (2009), the second part of Doctor Who crossover gag (2010), "suddenly, DINOSAURS" page (2011), The Beholder King answering a question about his plans (2012), and a page named "Explanations And Revelations" (2016).

Web Original
""They offered us just a shitton of cash,” said Graham Stark, President and co-founder of Loading Ready Run Megacorp Inc. “Like, you think you can imagine a shitton of cash, but you really, really can’t. We’re very excited to work with MauBau, the market leader of cat-focused entertainment content, to create great new entertainment properties. Also to get their money. Of which there is a shitton.""
 * The April 1 episode of Madd Man was not in fact about John Maddaloni trying to do a stunt and looking lame, but actually a fake trailer for a melodrama with hand puppets. Well, not puppets, just hands...it's easier if you watch for yourself.
 * Zero Punctuation's April Fools gags:
 * In 2009, the hosts of Unskippable pretended to stage a Hostile Show Takeover and reviewed X-Blades before Yahtzee seized the show back to review Halo Wars. Yahtzee also guest-commentated on Unskippable.
 * In 2010, the usually Motor Mouth Yahtzee recited Ode to Melancholy in a very slow, ponderous manner.
 * In 2012 Loading Ready Run announced that they would be renaming their site to "CatingCattyCats" to produce exclusively cat-related content for a Chinese company as part of a corporate takeover.

""This book is really long, and we are lazy. Sorry folks!""
 * In 2012, Grooveshark (a music streaming website) introduced a new feature where Hipster Otis and Hipster Jen pop up to offer inane commentary on any song you play.
 * On April 1, 2012, instead of an Animorph review, Cinnamon Bunzuh surprised everyone by releasing a review for Stephenie Meyer's The Host. Except when one actually clicks the review, it consists of nothing but an Andalite troll smiley (Which bizarrely actually works) and a note:


 * In 2016, the government of Canada posted Wolverine's war records - at least, the declassified ones - to the web. See them here.

Western Animation

 * In 2009, Cartoon Network replaced the majority of their programming with a surprise Cow and Chicken (a show which hadn't regularly been aired on the main network for years) marathon.
 * In 2010, they added fart and belch sound effects to almost every cartoon they aired throughout the day, even to the intros.
 * One year they ran the same Screwy Squirrel cartoon for twelve hours straight.
 * Infamously done with South Park's season 2 premiere in 1998; the audience was expection a resolution to Season 1's Cliff Hanger about who Eric Cartman's father was, but instead they got an entire episode dedicated to the farting Canandian Show Within a Show Terrence & Phillip that aired on April 1st. Reactions from viewers were quite negative, leading to Trey Parker & Matt Stone resolving the cliffhanger in the season's second episode. This was later Lampshaded in the episode Terrance & Phillip: Behind the Blow.
 * It was also referenced in the 2010 episode "Eat, Pray, Queef" which ALSO aired on April 1st. The creators actually originally intended to do a whole episode about the Queef Sisters, but went against it.
 * WeLoveFine, which sells licensed My Little Pony (mostly Friendship is Magic) and Jem merchandise, came out with My Little Pony hoof-hands and Jem and the Holograms projecting earrings in 2012. Trying to add either of them to your cart rewarded you with a 15% off code that lasted until Monday April 2nd 11:59pm.
 * Adult Swim. 2012. While it began with the introduction to The Room (which had been their joke in previous years), it quickly went in a different direction, bringing back Toonami for what was thought to be one night only. But then Adult Swim asked the fans what they thought on Twitter... They wanted their Toonami. As of May 26, 2012, they're getting it.

Real Life

 * Discover Magazine has published a number of notorious articles featuring absurd scientific discoveries, such as a macroscopic subatomic particle improbably named the "bigon."
 * The most infamous of these articles is the Hotheaded Naked Ice Borer, a fictional Arctic animal created for the holiday in 1995. The critter was briefly picked up as an actual news item by at least one other source, and there are anecdotes of inquiries by zookeepers looking for a specimen! Discover claims it has received more mail about this one article than any other it has ever published.
 * One dealt with a native culture that had "computers" by tying multiple knots in ropes using a system they had devised. Of course a little common sense applied showed that this was not only silly, but an Incredibly Lame Pun - they were knot computers.
 * Online tech news site The Register regularly put up joke articles on April 1st. The articles are usually gone by the next day however, although some of them are archived for posterity.
 * China, notorious for their censorship regime, bans the media in the country from publishing or airing fake articles and reports on April Fools' Day.
 * A popular joke is the "Fools' Day Parade", wherein someone announces a time and place and big acts for a parade that never happens. Some of the more entertaining press releases are of New York's "Annual April Fools' Day Parade", written by world-class prankster Joey Skaggs.
 * British newspaper The Daily Mail pulled one a few years back by claiming (then-)Prime Minister Tony Blair had replaced the black door of 10 Downing Street with a red one.
 * Many cable networks do April Fools' Day pranks. For example, Adult Swim will change their lineup or insert jokes into their programming: in 2005 it was fart jokes during Anime; in 2006 it was a "stealth premiere" of the finale of Perfect Hair Forever; in 2007 they aired the complete Aqua Teen Hunger Force Colon Movie Film For Theaters before its actual theatrical premiere date - in a small, 1 x 1 inch corner of the screen; in 2008 it was a whole night of "stealth premieres" and in 2009 it was the cable premiere of The Room. In 2010 and 2011, they aired The Room again. In 2012, they opted for a one-day revival of Toonami, which began with a Fake-Out Opening of The Room.
 * Memorably, the fart gag caused such an angry and immediate Internet Backdraft that the sounds were removed for the late-night second airing.
 * The Hotelicopter.
 * For 2008, the morning DJs at WBPM in upstate New York announced they were quitting. All throughout their show, they received calls from listeners asking if it was true and begging them not to do it. Just before they signed off, they admitted that they were quitting... smoking.
 * In 1989, the Seattle-based sketch-comedy show Almost Live did a mock broadcast claiming that the local landmark the Space Needle had fallen over in a windstorm. Their hosting station was forced to issue a formal apology.
 * In 2008, users of the Kubuntu Linux beta found that their wallpapers were now one of those Tastes Like Diabetes unicorn images. And that the dialog boxes for changing the wallpaper were disabled.
 * In the late 1980s, the U.S. Armed Forces Network (radio) in Europe celebrated April 1st with such news items as an invasion of Germany by giant grasshoppers. Also, the German "phrase of the day" feature was replaced with a cow phrase: "Moooo!" which means, "Hey, watch where you're putting those cold hands, buddy!"
 * Something about the radio business must really lend itself to these. From 1964, here's WABC's Dan Ingram being victimized during his on-air shift.
 * On April 1st of 2010, the cd trading site swapacd.com included a link on their homepage promising users "free credits". Instead of credits that can be exchanged for CDs, what they got were the kind of credits you see at the end of movies - a scrolling list of bad puns on names of famous actors.
 * All Things Considered, the evening news program of National Public Radio, does an annual April Fools news story, delivered in their usual deadpan style. Among others was a report on the dangers of exploding maple trees in Vermont one year, and then another was a reading outraged "listener mail" concerning Whale Farming (as in, raising whales in massive tanks in the Midwest) which was a long series of Completely Missing the Point gags.
 * The Swedish television channel SVT had a glorious one in 1962. Known radio technician Kjell Stensson told the viewers that by simply cutting up a nylon stocking and attaching it to the television screen, they would get color TV!
 * A few years ago one Christchurch newspaper published a news report about how the iconic Christchurch City Cathedral was going to be demolished due to bad structural damage. This became Harsher in Hindsight considering the catherdral was demolished in 2012 after a 7.9 earthquake struck the city.

TV Tropes

 * For April Fools 2011, all the avatars in the forum were changed to [[media:april fools 2011 spartacus 8552.png|a picture of]] Spartacus, and all usernames had "Spartacus" placed in front of them. After that, they began to rotate between several others, including:
 * A Stormtrooper's helmet, changing everyone's name to "Trooper [Troper's name]". [[media:april fools 2011 trooper 5853.png|april_fools_2011_trooper_5853.png]]
 * A Bear, with "Grizzly [Troper's name]". [[media:april fools 2011 bear 6305.png|april_fools__2011_bear_6305.png]]
 * A purple, butterfly-winged pony, with "Pony [Troper's name]". [[media:april fools 2011 pony 7896.png|april_fools_2011_pony_7896.png]]
 * Spider-Man, with "Spider-[Troper's name]". [[media:april fools 2011 spiderman 3825.png|april_fools_2011_spiderman_3825.png]]
 * Tweety Bird's head, with "Tweety [Troper's name]". [[media:april fools 2011 tweety 6095.png|april_fools_2011_tweety_6095.png]]
 * Serenity, with "Still Flying: [Troper's name]". [[media:april fools 2011 serenity 5847.png|april_fools_2011_serenity_5847.png]]
 * A blank space, with "Ghostly [Troper's name]".
 * And a Weeping Angel, with "Unblinking [Troper's name]". [[media:april fools 2011 unblinking 3564.png|april_fools_2011_unblinking_3564.png]]
 * April Fools' Day 2012 started a little bit early ("Somewhere on Earth it is April 1st") on this wiki, with the home page being translated to a random language, including Portuguese, Redneck, and Yoda.
 * For the Mohs Scale of Rock and Metal Hardness, some joker entered Hugga Wugga from The Muppet Show under Level 7 ("Soprano and gravel"), and Cookie Monster's C Is For Cookie (That's Good Enough For Me) under Level 9 ("Cookie Monster vocals - the Trope Namer"). Someone fell for it.

Anime & Manga

 * Demashita! Powerpuff Girls Z: The announcement that there was going to be a Magical Girl anime Spin-Off of The Powerpuff Girls was presumed as an April Fools joke due to being announced on said date.
 * More than that: it was announced on an April 1st, then nothing was said about it for months and months, with no new information to be had anywhere, until a follow-up announcement on, you guessed it, the following April 1st.

Comic Books

 * A few years ago, Marvel announced that Spider Girl had been Uncancelled on April 1st.

Film

 * The casting of Leonard Nimoy as the voice of Sentinel Prime in Transformers: Dark of the Moon was announced near April 1st. Extra skepticism points thanks to Nimoy's retirement from acting (which, as of this, clearly didn't stick).

New Media

 * Google's Gmail service was announced on April 1, 2004 with storage limits that (at the time) sounded absurdly infeasible; it was, of course, no joke. Since then, Gmail has run an April Fools' joke every year, including such "new features" as a free email printing service (subsidized by giant red context-sensitive ads on the back of the emails) and a feature allowing the user to send an email to days earlier.
 * And in 2007, a Google NY employee had to continuously state that despite the date, it wasn't a joke, that his 3 foot python really was loose in the building.
 * Popular gaming site The GIA suddenly announced its dissolution on April 1, 2002. Readers were confused for months before finding out that, yes, it really was closing down, and many were angry that they would pick April 1 of all days to make the announcement. The GIA was later retooled into the ill-fated GameForms.com, which didn't last very long and has now been replaced by a poker site.
 * Naruto the Abridged Comedy Spoof Series Show was meant to be one of these, but it ended up as a side project of LittleKuriboh's. It currently has 5 episodes.
 * That was 2009's April Fools joke. In 2008, he made a fake ending to the series and "moved on" to Zork and Pals. Then in 2010, he created "a Yu-Gi-Oh! 5D's abridged" with everyone just shouting "CARD GAMES ON MOTORCYCLES!!!"; then it turned out to be Iruka and Joekage watching it and then showing each other their abridged series. Naruto lampshades at the end how tired it's gotten and complains.
 * An accidental subversion: Gamefront (known back at the time of the incident as Filefront) announced on March 24, 2009, that they planned to shut down by the end of March. However, they managed to deal with their issues at that very moment and thus didn't close down after all; they just happened to be unfortunate enough to solve their problems by April 1st.
 * Like Naruto The Abridged Comedy Spoof Series Show, My Little Pony: Camaraderie Is Supernatural started as an April Fool's joke for 2011 from the creators of Sonic F. It got popular enough that another episode was made.
 * On April 1, 2010, Christian Chandler vandalized the CWCki, the site dedicated to him and his webcomic. Most users assumed it was a prank at first.

Tabletop Games

 * The official Magic: The Gathering website pulls off some sort of elaborate joke every year on April 1st, but occasionally hides some truth in it as well. Perhaps the best trick they pulled was on April 1st, 2004, when they announced Unhinged, a sequel to the popular Magic joke set Unglued. A few days later, it was revealed that the announcement was true.
 * Aaah, but when else to unveil new Unglued cards but that most auspicious of days?
 * The real Fool's Day Joke was the announcement that they were banning the Plains card: one of the resource cards you need to play the game.
 * In 2010, they put up an "Arcana" (mini-article) that was just a Long List of increasingly ludicrous rumors they want to debunk. Only the first 5 or so (of 38) were plausible enough to merit debunking.

Video Games

 * Def Jam Vendetta had an initial release date of April 1, 2003. Hardly anybody took seriously the idea of a Licensed Game where rappers beat the stuffing out of one another. The game actually met the April 1 release date, and it sold like hotcakes, inspiring a pair of sequels.
 * As with several earlier examples, the merger of Squaresoft and Enix was initially thought to be an April Fools' Day prank because it was announced on April 1.
 * Speaking of Square, Kingdom Hearts. Mickey Mouse and Cloud Strife in the same game? Shyeah, right...
 * Team Fortress 2's Jarate weapon for April Fools' Day 2009 is now a genuine weapon as of the Sniper vs. Spy update, release by the end of May 2009.
 * Valve have also made multiple Counter-Strike April Fools' Day updates.
 * On the subject of Valve again, 13 indie games on Steam saw odd updates relating to potatoes on April 1st, 2011. Surely enough, these potatoes served as the omen to something more sinister than a mere foolish prank...
 * Similiar to the Powerpuff Girls Z example above is Mario & Sonic at the Olympic Games, which was also announced near April 1st and thought to be an elaborate prank.
 * The newest version of Dwarf Fortress, two years in the making, was released on April 1, 2010. No surprise that the website broke within the hour.
 * Ogmo from Jumper has been announced to be a playable character in Super Meat Boy. The fact that Ogmo and Meat Boy himself are look-alikes left those who saw the news skeptical.
 * Narcissu -side 2nd- was supposed to be released on April Fools' Day. It got updated a few hours early, and some still think it's an April Fools' Day joke.
 * One April Fools Day, Max Barry announced that the UN-like organization in his browser-based nation simulation game NationStates would change its name to the World Assembly because of a complaint from the real UN about his use of the name and emblem. Turns out, the UN really did send him a letter, and the change was made to comply with it.
 * Hatoful Boyfriend's introduction states that the character designs were released on April Fools' Day, and there's an anecdote (could be truth, could be just an Urban Legend) that the creators of this game had originally intended for the game to be a normal Dating Sim with human guys and posted bird designs for these guys on the website as an April Fools' joke, only for fans to love them so much that the game ended up being all about dating birds instead.
 * Roxio announced an Angry Birds animated series on April 1st 2012.
 * Whilst League of Legends usually plays this straight, a notable subversion was the announcement of the long awaited champion Lee Sin, the Blind Monk who was released a few days later. In the April Fool's version, he was indestructible and could kick across the map but the player was filtered through a blurry screen. Here's the April Fools spotlight compared to the real spotlight.

Web Comics

 * Subverted in 2010 by Looking for Group who chose April 1 for some real yet unlikely plot development. It would seem that two party members met long ago, but the sane one was too badly hurt to remember in detail.
 * Loserz brought us this strip. Jodie completely naked!
 * After several months of Megatokyo being almost entirely Miho and Piro talking, April 1st, 2012 unexpectedly delivered a barely offscreen naked Magical Girl wrestling match and Piro getting smacked in the face with a washbasin. Canonically.

Web Original

 * The Other Wiki features a set of articles each April Fools' Day, and despite their absurdity, each of them are true. Of course, the site also runs rampant with pranking, such as changing all the links on the Rickroll article to point to, well, a Rickroll.

Real Life

 * Marvin Gaye was shot and killed on April 1, 1984 by his father. People were shocked the next day because then they knew it was true.
 * People did not initially believe Tazz's departure from WWE was real because it was so close to April 1.
 * You have to see this to believe it: Uni Watch Blog, a website dealing with sports uniforms, posted a prank article on April 1, 2009, claiming that a certain NFL team was going to adopt a lime green alternate jersey; the prank fooled the makers of Madden NFL 2010, who inserted the uniform into the game. Cue the September 28, 2009 game between the Seattle Seahawks and the Chicago Bears, and the Seahawks wore lime green uniforms.
 * "Think Geek" added a Tauntaun sleeping bag to their catalog as an April Fool joke ... but response was so great they're now checking with Lucasfilms about making that bag for real. (They got permission.)
 * The same happened with the Personal Soundtrack t-shirt, which was an April Fools' Day joke that was so popular they ended up actually making one.
 * Same with their ever popular 8-bit tie.
 * Following a shift in power at CBS and complaints over his appearing to be overly power-hungry, sportscaster Brent Musburger ended up getting fired on April Fools' Day 1990, with his calling the NCAA Basketball Championship game serving as his lame duck assignment prior to joining ABC Sports.
 * The death of comedian Mitch Hedberg was questioned because it was announced on his website on April Fool's Day.
 * Steve Jackson Games had an announcement about the long-desired Ogre update on April Fools Day 2012. But it wasn't a joke, the wargame was being republished. (The Kickstarter campaign was fully funded before the formal announcement.)

Anime & Manga
"Ms. Kuroi: Sorry, Izumi. I deleted all your saved data. Konata: WHAT?! Ms. Kuroi: Fooled ya, fooled ya, today is April Fools! Konata: She must be so bored calling up this late."
 * The Melancholy of Suzumiya Haruhi had an April Fool's day episode where Achakura tries and fails to trick Nagato several times.
 * Keroro Gunsou has a chapter where the Platoon fools Fuyuki and Natsumi into thinking they have gotten serious about their invasion of Earth - they even hijack some news broadcasts and internet sites to amplify the effect of their supposed attacks on the population. It even includes a number of Shout Outs to Orson Welles' radio adaptation of War of the Worlds.
 * An arc in Lucky Star has a few.
 * a phone call between Konata and Kagami has Konata claiming to have finished her homework by herself, shocking Kagami... until Konata revealed that it was an April Fools' Day lie.
 * After the call, Kuroi-sensei called Konata, tricking her into thinking she'd saved over game data:

"Tsukasa: What I said just now... I lied... when I said I lied?"
 * Then Konata told Kuroi that Miyuki had used her as an example of why being a teacher must be an easy job.
 * Meanwhile, when asked, Tsukasa tries her hand at a recursive April Fool's lie, confusing Kagami a bit:

Comic Books

 * The Batman story Arkham Asylum: A Serious House on Serious Earth takes place during April Fools' Day. Early in it, The Joker tells Batman that he's going to shove a pencil in a girl's eye (which later inspired a Joker in a different adaptation), only to later reveal he was just april fooling Bats and the girl is fine. According to Word of God, Two-Face doesn't shoot Batman in the comic's last page despite getting tails from his coin because it was April Fools' Day.

Film

 * In the 1939 film Goodbye, Mr. Chips, the boys of Brookfield school play pranks on the masters on April first, and the eponymous Mr. Chipping's wife goes into labour.
 * Featured in the Slasher Movies April Fools Day and Slaughter High, plus the lesser known ones April Fools and Killer Party.

Literature

 * In Billy and Howard, the twins play jokes on each other. Hilarity Ensues, for certain values of hilarity.
 * In The Confidence Man, it is April Fools' Day when a mysterious man sneaks onto a steamboat and tests each passenger's confidence through moral questioning while conning them out of their money one by one.
 * According to Word of God, Fred and George Weasley were born on April 1st.

Live Action TV
"Lister: A hundred and eighty billion pounds? You're kidding! Holly: (suddenly wearing Groucho glasses) April fool. Lister: But it's not April! Holly: Yeah, but I could hardly wait six months with a red hot jape like that under me belt, could I?"
 * A first season episode of Community had a plot centered around Britta's attempt at an April Fool's Prank, after being called a 'killjoy' one too many times.
 * In a Season One Red Dwarf episode, Holly tells Lister that an attack fleet from the Norweb Federation is after him for his crimes against humanity—he left two sausages to go mouldy three million years ago, and they now cover nine tenths of the Earth's surface. They also have a final electricity demand for £180 billion.

Newspaper Comics

 * An old Peanuts strip has Lucy coming up to Charlie Brown at school recess and telling him the little red-haired girl wants him to come over and eat lunch with her. Charlie Brown nervously walks off, then - after a Beat panel - returns to shoot a Death Glare at Lucy as she says, "April Fool!"
 * This FoxTrot strip, involving Jason watching the season premiere of Game of Thrones, only for HBO to put on a joke episode with My Little Pony Friendship Is Magic toys. It has to be seen to be believed.

Western Animation
"Lou: We need pretzels. Repeat, pretzels."
 * Nicktoons:
 * The Wild Thornberrys had an episode about April Fools' Day with Eliza and Tyler pulling pranks at each other.
 * Ditto SpongeBob SquarePants. It's his favorite holiday!
 * Add CatDog ("Kooky Prank Day") and The Fairly OddParents ("Fool's Day Out") as well.
 * The Fairly OddParents had a semi-recurring character called The April Fool who is the personifacation of April Fools' Day (like The Easter Bunny or Baby New Year for Easter and New Years) and talks like a Jerry Seinfeld stand-up act ("What's up with that?").
 * As did Hey Arnold!, where Arnold finally gets one up on Helga, with plenty of over-the-top flirting on Arnold's part as he does so - probably influenced by the post-movie feelings inferred that Arnold has for Helga starting to surface.
 * The Simpsons: the first clip show used April Fools' Day as a framing device. Bart, trying to outprank Homer, puts a can of Duff in a paint shaker. The ensuing explosion of high-pressure beer puts Homer in the hospital, where the family talking about his past experiences triggers the Flashbacks.

"Tom Tucker: Yes, April Fools. We, at Channel 5 News conducted the whole black hole story as part of our commitment to be infestive around the holidays. Diane Simmons: And with only eighty-seven suicides and widespread looting, we think this was a pretty successful practical joke! Brian Griffin: You DICKS!"
 * The Family Guy episode "April in Quahog", when the newcasters tell the city that Earth is going to be destroyed by a black hole within a day.


 * The episode also contained a real-life April Fools' Day prank, as it was announced that Stan and Francine Smith and Hank Hill were going to guest-star, but they didn't.
 * On Jimmy Two-Shoes' Alternative Calendar, the holiday is Lucius Fools Day, where Lucius pulls mean-spirited pranks on everyone (as opposed to his usual Kick the Dog mentality).