A professionally-published story that evolved from Fanfic. This can overlap with Serial Numbers Filed Off, but it is by no means necessary. The setting of the new work will often be suspiciously similar to the source material for obvious reasons, but the plots of the two stories can come out very different indeed. Alternatively, a number of these began as Transplanted Character Fics, which are easier to publish professionally as the only connections to the original canon are character personalities and inter-relationships that are too vague to be covered by copyright. A Promoted Fanboy might even rework his fanfic as an official part of the franchise.
On occasion, a fanfic becomes its own legitimate franchise without bothering to cut all its ties to the original, complete with its own fanbase outside fans of the original, with the blessing of the original work's copyright owners. In some cases, some fans may not even realize that it was a derivative work.
In other media, this can applied to video games that originated as unofficial fan games or Game Mods.
Compare Spiritual Successor, where a work doesn't violate copyright law, but fans consider it to be very similar to some preexisting work. See also Humble Beginnings, of which this can be considered a subtrope.
Contrast Ascended Meme and Ascended Fanon, where derivative material is later incorporated into the canon material, and the similar Running the Asylum, where fans gradually take control of the original franchise as time goes on and start publishing official material that looks like fan fiction. Also compare Canon Immigrant and Ret-Canon, where the new elements stem from official sources. See also Serial Numbers Filed Off, Divorced Installment, What Could Have Been, and Captain Ersatz.
- Nyoron Churuya-san started as a series of Haruhi Suzumiya-themed doujinshi comics. Churuya-san would later be officially published in Comp Ace, and it even got adapted into a net animation at the same time as the official Haruhi Gag Series Haruhi-chan did.
- Petit iDOLM@STER was originally a fan comic published on the author's website. It would later become an official spinoff of The iDOLM@STER and get its own anime adaptation.
- The Japanese drama CD Yours for an Hour surprisingly started out as a American slash fanfic of Naruto. It went as far as using Junko Takeuchi and Noriaki Sugiyama for the leads.
- The founders of Big Finish Doctor Who were part of the Doctor Who Audio Visuals fanwork community, and five Audio Visual plays were remade by Big Finish, with another getting a Stealth Sequel.
- Greg Rucka's espionage series Queen and Country is an acknowledged ascended fanfic of the British TV series The Sandbaggers.
- The Last Hope was an unlicensed Gamera dōjinshi made as a fan prequel to the Heisei Gamera films. The Japanese translation of Gamera: The Guardian of the Universe in 2018 included The Last Hope as a bonus (on top of also having the cover illustrated by the same artist), and the studio that releases Gamera films considers the story canonical (also meaning that the previously unused Showa kaiju Garasharp, which features in the comic, is retroactively made canon as well).
- Guillermo del Toro stated in an interview that The Shape of Water began life as some doodles he made after seeing Creature from the Black Lagoon as a child, when he wondered "why couldn't the fish monster and his beloved be happy together?". And so, many years later, came an Oscar-winning film.
- The Despecialized Edition restorations of the Original Star Wars Trilogy have since been used for some theatrical screenings of the Star Wars Trilogy since the Lucasfilm acquisition.
- Young Adult author Cassandra Clare started off as a fanfic author and later used lines from her own fanfics in her original work.
- Doctor Who and Doctor Who Expanded Universe examples:
- The fourth Doctor Who New Adventures novel, Timewyrm: Revelation, with the Seventh Doctor and Ace, came out of a Fifth Doctor and Tegan fanfic published in a fanzine. Paul Cornell expanded and changed quite a bit and made it into his first novel.
- The Highest Science, an early NA by Gareth Roberts originated as a crude fan story. It turned into his first novel. This, in turn, formed the loose basis for the television story "Planet of the Dead", which he cowrote with Russell T. Davies.
- The Left-Handed Hummingbird by Kate Orman began as a fan fiction for the Australian fanzine Pirate Planet.
- The Bernice Summerfield novel Deadfall by Gary Russell was based on his Doctor Who Audio Visuals play of the same name. In addition, Russell included a number of references to Audio Visual continuity as Cryptic Background References throughout his novels.
- The Vorkosigan Saga, was at a very early conceptual stage Star Trek fanfiction; Beta Colony and Barrayar are reminiscent of the Federation and the Klingon Empire, respectively. Of course, it diverged away and became its own universe almost immediately.
- "Negri's Boys" by Charles Coleman Finlay, which was originally fanfic of Bujold's work, was rewritten with the serial numbers filed off as "The Political Officer". It was published in The Magazine of Fantasy and Science Fiction and nominated for the Hugo and Nebula Award.
- This is Naomi Novik's origin story for the Temeraire series:
"...it was started on January 8, 2004, about ten days before I sat down to write a different fantasy AU story and suddenly went, you know what, this isn't so much Fan Fic anymore, and these aren't Jack and Stephen, ("this is not my beautiful house") and off I went to frolic with dragons."
- Novik's Sherlock Holmes fic-turned-published-pastiche, Commonplaces, is another example.
- Harry Turtledove's Videssos cycle began as Fourth Age The Lord of the Rings fanfic.
- Fifty Shades of Grey used to be a Twilight Mundane-AU fanfic named Master of the Universe.
- Examples of "pulled to publish" fanfics plague the Twilight fandom: here is the list.
- Devil's Brand, Casea's Major's thinly-veiled work of Fifty Shades fanfic, making it an ascended fanfic of an ascended fanfic!
- Dennis L. McKiernan's Mithgar novels (The Iron Tower, The Silver Call, Hel's Crucible) started off as The Lord of the Rings fanfic. Doomsday wanted to publish. Tolkien Estate said "no". Changing the names and filing the numbers off for the "Silver Call" duology required inventing a new backstory of a great war against evil to replace The Lord Of The Rings, and thus the Iron Tower trilogy came about. The rest of the series grew more divergent from there, but the Moria-analogue in those first books is unmistakable.
- Star Trek: The Original Series examples:
- Some (most?) of the Star Trek: The New Voyages anthologies came from stories originally published in fanzines.
- The 1983 tie-in novel Killing Time by Della Van Hise was and still is thought to be originated as Slash Fic about Kirk and Spock. The truth is, according to author Della Van Hise, the original printing was from a non-proofed, and therefore "not approved by Paramount" manuscript accidentally sent to the printer. Paramount discovered this and ordered the first printing run pulpednote . An edited second printing came out shortly thereafter wherein most changes were minor single sentence or word changes designed to reduce the subtext. But this led to unstoppable rumors that an original, explicitly K/S, version of Killing Time exists. The author says, "There is no such manuscript."
- Barbara Hambly's novel Ishmael (1985) is a crossover between Trek and the Western TV show Here Come the Brides (1968-1970). (It's inspired entirely by the fact that actor Mark Lenard appeared in both series.) According to Hambly, she dug her original fanfic out of a drawer when she heard Pocket Books was looking for Star Trek authors, and in fact offered to rewrite the setting as a generic Western, but the editor told her it wasn't necessary.
- Divine Blood Novels was originally a Mega Cross Over fanfic of several anime (most notably Ranma ½, Full Metal Panic!, and Ah! My Goddess) which eventually developed enough mythos and themes of its own that the author decided to file off the serial numbers on the characters and make it into its own novel.
- Many lesbian romantic novels of the early 2000s started off as Xena: Warrior Princess Xena/Gabrielle Transplanted Character Fics, known in the Xena fandom as "uber" fics. Tall, dark-haired, bitter woman meets sweet, good-natured blonde, and romance ensues? It just might be an uber.
- There's also a few uber-Glee lesbian novels starring the equivalents of Quinn and Rachel ("Faberry").
- Captive of the Red Vixen started out as an AU fanfic of the webcomic Terinu where Melika (renamed Melanie Lovejoy in the final draft) became a pirate.
- Dog And Spider Private Investigations was actually originally a short story lead-in to a Marvel Universe RP campaign. Every player was to write a story as to how their character joined the main campaign. The author, who was going to play Spider-Woman, was the only one who wrote anything of note. At the encouragement of the group, he took that short story and turned it into an entire series. Jessica Dombrowski's origin story and dialogue in the first 30 pages or so of book one become more obvious if you know this, though the series diverged heavily thereafter.
- Spectral Shadows started out actually as a sequel fanfic to Bambi, but when Disney was able to retain the rights to the original Felix Salten novel and its characters, the creators ended up crafting their own story out of what they had at that point.
- After by Anna Todd started out as a One Direction fanfiction about an OC falling in love with band member Harry Styles.
- The British SF writer Suzanne Palmer published an early short story called "Concession Girl", which was blatantly a first-season Babylon 5 fanfic with the character names changed and the alien characters made less humanoid. Despite this, any B5 fan will instantly recognise Londo, G'Kar and Garibaldi. The Garibaldi character even retains the initials MG. Cheekily, fandom culture at the time would almost certainly have denounced the story as too self-centered (the original-character female protagonist saves "Londo" and "G'Kar" from a human-chauvinist terrorist attack and ends up dating "Garibaldi").
- A Symphony of Eternity started out as crossover between Flashman and Code Geass before evolving into a Space Opera that uses magic instead of technology and ramping up the conflict to a galactic scale. Oh, it also has a Death Star with two energy beams.
- The Wayward Astronomer by Geoffrey Thomas started off as a fanfic for Dreamkeepers that became an official Dreamkeepers work.
- Morning, Noon & Night by Michael Payne started as a My Little Pony: Friendship Is Magic fanfic, Half the Day is Night. It was heavily rewritten, all the characters changed to non-pony species (unicorns become humans, pegasi become birds, earth ponies become dogs) and published on Amazon.
- Popcorn Love by KL Hughes started as a Once Upon a Time Transplanted Character Fic with no magic whatsoever - businesswoman and single mother Elena Vega was originally Regina Mills, her three-year-old son was a three-year-old Henry Mills (albeit with a different origin, in that he was actually Regina and Daniel's son, rather than being adopted), and Elena's new babysitter, NYU senior and eventual love interest Allison Sawyer was Emma Swan.
- Goblin Slayer began life as a D&D mod, but while getting stuck on how to write it out, the author turned it into a novel instead.
- Salvation: Dawn of War very clearly started life as a Megatron/Starscream fanfiction. Even the character names are similar.
- Peter Watts' Hugo-nominated short story "The Things" doesn't even try to hide the fact that it's a Perspective Flip fanfic of The Thing (1982) from the alien's point of view.
- Last and First Idol began as a Love Live! fanfic before going on to become a Seiun Award winning short story.
- Cecilia Johanna's novel Underground began as a Final Fantasy XIII-2 street fighting alternate universe fanfic for the Hope/Lightning ship. It got so popular she decided to remove it from the internet, change the names, and publish it as an original romance novel.
- The notoriously litigious Addison Cain's Born to be Bound, one of the first major published Omegaverse stories, started life as a fanfiction of The Dark Knight Rises. In its published form, there's still a lot of similarities—the setting is a city that's been walled off from the outside world, the male lead is a muscular crimelord with an anarchistic political philosophy, the frozen-river execution is maintained, quite a few characters are analogous to ones in the film, and there's even a clear paraphrasing of Bane's speeches about being born in the dark.
- The Angel of the Crows by Katherine Addison is very clearly a take-off of Sherlock Holmes, in which "Holmes" aka Crow is a not-quite-fallen angel and "Watson" aka Doyle is a hellhound, but according to Word of God it started life specifically as a Sherlock fanfic.
- Spirit of the Northwest is a Distant Sequel of Here Come the Brides published as a novel.
- The Love Hypothesis is about a Ph.D. candidate who fake-dates a moody professor, only for the two to fall in love for real. This started out as a Kylo Ren/Rey Mundane AU fanfic.
- The Record of Lodoss War franchise started out as edited accounts of a Dungeons & Dragons campaign, which were published as a series of novels. The novels quickly became popular enough to spawn their own game system, manga, multiple OVAs, and a television anime.
- La Profecía de las Espadas, an epic high-fantasy 1000+ page novel by Spanish author Helena Ramírez, was published February 2023 more than 10 years after first appearing as a fanfic from Lyrical Nanoha and originally known as La Leyenda de la Espada del Día y la Espada de la Noche.
- Lancelot of the Arthurian Legends came by way of French storytellers. Percival was an OC. It could even be said that the entire Arthurian Canon is, in its own way, fanfiction.
- Older Than Feudalism: The Aeneid, widely hailed as the first work of literature ever and the model for much that came after, was basically a Perspective Flip fanfic continuation of The Iliad.
- Dungeons & Dragons is something of a strange case. The game borrowed heavily from J. R. R. Tolkien (and a few other fantasies, such as Jack Vance's Dying Earth series, Poul Anderson's Three Hearts and Three Lions and Fritz Leiber's Fafhrd and the Gray Mouser series), as well as various more obscure mythologies, but had many unique elements as well. The franchise owners have ended up splitting the game rules into "trademarked material" and "open source material", and encourage others to develop derivative material based on the open source components. In addition, the owners have also licensed derivative settings that have gone on to become book or video game series enjoyed by readers who aren't necessarily fans of the pencil and paper game, including Dragon Lance, Greyhawk, Forgotten Realms, Planescape, Ravenloft and Spelljammer.
- The Elder Scrolls setting was originally a home-brew Dungeons and Dragons module.
- Ditto for Malazan Book of the Fallen, which originated as the two creators' home-brew setting.
- Rhapsody Of Fire based epic storylines of their songs on their D&D campaign.
- Forgotten Realms were born as a setting before voluntarily going under Dungeons & Dragons, though fleshed out mostly after. Whether basic (Greyhawk) rules were more of inspiration or problem is up to Ed Greenwood — he both constantly kicked them aside and used new edition change for the "Time Of Troubles" overhaul.
- Renegade Legion was originally set in the Star Wars Legends.
- After the Bomb was originally created for Teenage Mutant Ninja Turtles 'verse.
- The International Super Teams setting for GURPS had its genesis in an unused timeline and history written for a Villains & Vigilantes campaign in which the author was a player.
- Warhammer 40,000:
- Castus Grendel, the low-level acolyte who tried to delay for one round a daemon that can eat Space Marines for breakfast. Grendel ended up decapitating it in one hit with a simple knife purely on a blessing of Random Number God (or maybe the God-Emperor?). Then this hilarity continued to absurd degrees and beyond. Started as an amusing session report, ended up mentioned in canon material (the last link in that article).
- Rocks Are Not Free!, a deconstruction of the Colony Drop tactic, was later published in GW's White Dwarf magazine.
- The fanmade Astartes was not only made an official GW product, the original Retributors chapter was made canon as well.
- The Nintendo 3DS Version of VVVVVV includes 18 fanmade levels, and canonizes those levels.
- One of the most prominent examples in all of video gaming: Ms. Pac-Man was originally an unofficial Game Mod of Pac-Man named "Crazy Otto", which introduced more complex mazes and semi-randomized elements into the ghost's AI. The mod creators, General Computer Corporation, thinking they might have had a successful game in its own right at their hands, ended up approaching Midway Games, the company holding Pac-Man's North American distrubition license, to show off their project. Midway was impressed with the modders' work and struck a deal with them, converting their project into an full-on Pac-Man sequel, and were also the ones to come up with the idea of having the game feature a Distaff Counterpart of Pac-Man. Although this was originally done without Namco's consent, Namco president Masaya Nakamura was eventually brought in on the project by Midway and would provide feedback on the player character's design. The character and others inspired by her would later appear in various official Pac-Man media.
- Save for the Half-Life series, all Valve Software works were developed from fan mods:
- Team Fortress Classic is an official sequel to a Quake mod, which was ported to Half-Life's engine. As is Team Fortress 2, by extent.
- Counter-Strike? It was a Half-Life mod. So was Day of Defeat.
- And Left 4 Dead was originally inspired by a zombie mod for Counter-Strike.
- Portal was inspired by the student project Narbacular Drop, and the gel mechanic in Portal 2 was developed from Tag: The Power of Paint (Valve hired the entire programming team of the latter). Also, the Xbox 360 Updated Re-release Portal: Still Alive contained some levels from the mod Portal:The Flash Version MapPack.
- Alien Swarm and Dota 2 also count, having originally been mods for Unreal Tournament 2004 and Warcraft III respectively.
- Dota Underlords is derived from the popular Dota 2 mod, Auto Chess, which makes it a triple-recursive Ascended Fanfic.
- The Game of The Year Edition of Unreal Tournament contained the mods Rocket Arena: UT and Chaos: UT. There were plans to also include a mod version of Tactical Ops: Assault On Terror, which didn't made the cut.
- The Translocator in Unreal Tournament 2003 and later has a remote camera within the transport-destination disk. This idea was taken from "Translocam", a mod that added this functionality to the classic Translocator.
- The Bombing Run gametype is inspired by the Fragball mod for Unreal Tournament.
- The Instagib Shock Rifle gained a zooming ability which appeared first in the "Zoom Instagib" mod for Tournament.
- The "Editor's Choice Edition" of 2004 also included the fan-made mods Air Buccaneers, Alien Swarm, Chaos: UT2, Clone Bandits, Deathball, Domain 2049, Frag.Ops, JailBreak, Red Orchestra, Rocketeer and UnWheel.
- The Mega Bonus Pack for 2004 canonizes six fan-made maps, four for Assaultnote and two for Capture the Flagnote . There were plans to get another Assault mapnote for the pack, but were dropped due to the map not being finished in time. Coincidentally, these maps were among the finalists and winners for the first "Make Something Unreal Contest".
- Unreal Tournament III has the Greed mode from the Titan Packnote , which started as a mod for Unreal Tournament 2004. His creator, Mysterial, is now working for Epic Games.
- This is the entire point of Unreal Tournament 4, said to be a collaboration between Epic Games and the Unreal community.
- The Translocator in Unreal Tournament 2003 and later has a remote camera within the transport-destination disk. This idea was taken from "Translocam", a mod that added this functionality to the classic Translocator.
- Hours before the Doom modification WAD "Evilution" was set to be released, the creators, Team TNT, were emailed by John Romero offering a publishing deal. It ended up as half of Final Doom. This decision, however, resulted in a Broken Base: many players were thrilled to see a fan production become canon, while others accused Team TNT of "selling out" their fans.
- One of the most common types of mods created for Doom 3 was the kind which allowed the player to use their gun and their flashlight at the same time. For the BFG Edition, id gave the player a flashlight that is attached to the player character's armor, allowing you to use it without putting away your weapon.
- The Glory Kill mechanic in DOOM (2016) is obviously based on the execution mechanic from Brutal Doom. Mods to upgrade and improve weapons are hidden around the levels, similar to Doom, the Roguelike. Argent Energy, Earth's reliance on it as a clean and bountiful source, and the UAC harvesting it leading into the demon invasion is extremely similar to the lore in Hideous Destructor. And the lore of the Doom Slayer joining the Argenta military to help destroy demons infesting countless other dimensions implicitly means every mod made for the classic games is canon.
- Red Orchestra, Killing Floor and Alien Swarm were all originally mods for Unreal Tournament 2004. The developers of the first founded Tripwire Interactive, who also published the second. The developers of the third were hired by Valve and eventually ported it to the Source engine.
- Killing Floor also tends to make some well-made custom maps official through patches.
- Tower Defense began as mods for StarCraft and Warcraft III but later became a standalone genre.
- Fall from Heaven: Age of Ice was included in "Civilization IV: Beyond The Sword."
- Trouble in Terrorist Town started as a simple game mode for Garry's Mod, but it went on to win the Fretta contest (a contest to see who could win the best gamemode using the new gamemode framework, called Fretta) and grew in popularity so much it now comes with the game.
- The "Fudge Pack" and "10th Anniversary" releases of Postal 1 and Postal 2 include the Eternal Damnation and A Week in Paradise mods for the second game. The later digital releases of Postal 2 were patched to also include A Week in Paradise by default
- Tempest Tubes was a popular unofficial hack of Tempest that Atari ended up distributing officially.
- Dragon Quest I was a VERY thinly-veiled d20 game in the style of Dungeons & Dragons.
- Final Fantasy was also heavily inspired by D&D, to the point that they had to edit a few monsters because of copyrights (the Eye◊ was originally a Beholder◊). FFI and Final Fantasy III also used a spell system with "levels" of spells based on D&D's caster classes, but sequels (and later remakes) changed this to Magic Points.
- Street Fighter X Mega Man was a Mega Man (Classic) fan game that eventually became officially endorsed by Capcom themselves.
- One of the most popular types of mods for multiplayer first-person shooters is "zombie mode". For Call of Duty: World at War, Treyarch decided to skip a step and just implement a zombie mode from the get-go.
- Escape Velocity Override began as a total conversion to Escape Velocity (that's actually where there name comes from: the mod developer called it Override since it would override the old game datanote , and the name stuck) before the developers of the original adopted it, updated the engine and published it. The same happened for Escape Velocity Nova, which started as an Override TC.
- The Steam release of 7.62 High Calibre includes the Blue Sun Mod and the fan-made extension 7.62 Hard Life. The former is enabled or disabled through checking an option in the Steam's options of the game, while the latter is technically a stand-alone game included in each 7.62 High Calibre purchase.
- Mount & Blade: Warband DLC Viking Conquest is basically the mod Brytenwalda converted as an official campaign by Brytenwalda creators.
- The Stanley Parable was originally released as a Half-Life 2 mod with most graphical assets reused from that game, then re-released commercially with original graphics.
- Them's Fightin' Herds started its life as Fighting Is Magic, a Fighting Game based on the My Little Pony: Friendship Is Magic cartoon, by a group of fans called Mane6 using the 2D Fighter Maker. After a cease-and-desist sent by Hasbro, Mane6 decided to continue the project, but with original characters and a new universe. The creator of the MLP:FIM cartoon, Lauren Faust, was hyped about the original game and offered her help in designing new characters to the new game. Additionally, Lab Zero Games gave them a license to use the Z-Engine, a professional Game Engine, in substitution of 2D Fighter Maker, a Game Maker. Now the group of fans constitute an actual company, Mane6, Inc, and their game will be released commercially.
- RWBY: Grimm Eclipse started out as a fan-made effort, but was picked up by Rooster Teeth and made into an official Licensed Game.
- Freedom Planet initially began life as a Sonic The Hedgehog fan game. With high-speed platforming, and looping roller coaster level designs, and the character designs are very Sonic-esque, but ultimately grew into its own beast entirely. It was successfully Kickstarted and released in 2014, and is getting a sequel.
- The Binding of Isaac: Antibirth is a popular Game Mod for The Binding of Isaac: Rebirth that adds a multitude of new floors, songs, weapons, and bosses to the already meaty base game. Naturally, once word got out that the Afterbirth+ expansion would include an official modding suite, the Antibirth dev team received a quite a few requests from fans asking them to port the new content they added into the Afterbirth+ engine. However, this wasn't deemed technically feasible with the limitations imposed by the modding kit, and that seemed to be the end of it for a few years. In September 2018, though, came the surprise announcement of The Binding of Isaac: Repentance, a second set of DLC for Rebirth that canonizes all of the content from Antibirth and adds in some new things of its own.
- The retraux 3D platformer Zera: Myths Awaken started out as Spyro: Myths Awaken. It was originally a Spyro The Dragon Fan Game and a Fan Sequel to Spyro: Year of the Dragon. After the project was given a cease-and-desist, it was rehauled into a Spiritual Successor instead.
- Oddity was originally a Fan Sequel to the Mother series known as Mother 4. It was eventually rebranded as a new IP: partly to avoid potential legal issues with Nintendo, but also because the developers recognized that they were really making an original game anyway, with the Mother series elements having little reason to exist.
- The cat sim Cattails is a retool of the Warrior Cats Fan Game Warrior Cats: Untold Tales.
- Zig-zagged with the Neverwinter Nights premium modules Darkness Over Daggerford and Tyrants of the Moonsea. Originally slated to be ommercially released premium modules, they ended up released for free after the premium module program was canceled. However when the Enhanced Edition of the game was released, the modules got an overhaul of their own with bugfixes and added content and were finally released as paid premium modules.
- Five Nights at Freddy's gives us the Fazbear Fanverse: A project where Scott Cawthon funds a few fan-games so they can get console ports, mobile ports and merchandise, making those few fan-games official, but not canon to the FNAF lore.
- Gun Game, a popular FPS gamemode mod where players progress through a list of in-game weapons, gaining a new weapon with every set amount of kills until they're at a final level (usually a melee weapon of some variety), has been a staple modded gamemode of most FPS games ever since the original Counter Strike. Eventually it was added as an official mode to CS:GO(), Valorant, and Halo Reach, Halo 4, and Halo 2 Anniversary's Multiplayer via the Master Chief Collection (renamed "Arms Race" for the former, and "Escalation" for the latter 4 games).
- The Forgotten City started as a popular quest mod for The Elder Scrolls V: Skyrim, and then got remade as a standalone title. The standalone version recreated some gameplay and mechanics from Skyrim, but with some new differences and the setting changed from a secret Dwemer city to ancient Roman times.
- Super Lesbian Animal RPG evolved from a My Little Pony: Friendship Is Magic fangame made using RPG Maker titled Super Lesbian Horse RPG. In its current incarnation most of the original characters are so different from the ponies they replaced that it's nigh-impossible to guess who replaced who in most cases. But there are some artifacts from SLHRPG, for instance the Cutie Mark Crusaders acted as equipment merchants in the old game and SLARPG's starting town merchants are still a pair of kids.
- Path of the Midnight Sun began as an alternate universe Game Mod of Fire Emblem: The Sacred Stones featuring an original cast of characters and story. The majority of these characters and plot elements remain in the finished game, albeit with vastly different gameplay mechanics, such as hunger and sanity effecting combat, a timed clock that alters story events, and a row-based battle system.
- Drowtales was originally a Forgotten Realms fanfic.
- Dan and Mab's Furry Adventures started off as a comic using the characters played by a group of friends in the Furcadia online chat/roleplaying client. Early strips have a lot of reference to roleplaying terms, game mechanics, internet fads and the like, before it grew into its own setting and story.
- Freighter Tails was originally called "Haul Trek", but the authors remade it, removing all the Star Trek elements in the process.
- Whatever it might have become, it's fairly obvious from the first strip that Looking for Group was originally a World of Warcraft comic. Things went full circle when the backers suggested a video game was made.
- Awkward Zombie had a strip about turning itself into an Ascended Fanfic, but it turned out to be onetime gag and the series went back to using Smash Bros. characters. The author also pulls strip ideas from the forums pretty frequently, and even has a thread for the purpose.
- Arthur, King of Time and Space is based on King Arthur In Time And Space, which in turn was based on Star Trek/Doctor Who crossover fanfic cartoons with the proper names search-and-replaced (Arthur, Lancelot and Guenevere replacing Kirk, Spock and McCoy; Merlin and Nimue subbing for the Doctor and various companions).
- Mico Verse started life as an Eddsworld fancomic.
- Chakona Space started out as a Star Trek fanfic. It has retained most of the technology and the Caitian race, but almost everything else is original by now.
- The racy Monster Girl Encyclopedia series started out as a Dungeons & Dragons style Moe Anthropomorphism bestiary, but soon statred adding more original creatures to the roster (though characters like the Gazers and Beholders are still runnung around).
- To Belong started out as a series of Transplanted Character Fanvids featuring various characters from animated films. The creator has decided to make it into a web-cartoon by giving everyone new designs and changing their names.
- The Gender Flip "Fionna and Cake" episodes of Adventure Time were based on What If? comics created by the show's character designer, which were in turn based on the Rule 63 images on 4chan.
- The "The Cat that Laid the Golden Hairball" episode of Ren & Stimpy was based on a fan comic that had been mailed in to Spumco.
- A 26th season The Simpsons episode, "Bart's New Friend", is based on a fan script written by Judd Apatow. The plot is about Homer being hypnotized into acting like a ten-year-old.
- The character of Newtralizer in Teenage Mutant Ninja Turtles (2012) came from Executive Producer Ciro Nieli's elementary school drawings.
- Rick and Morty began as "The Real Animated Adventures of Doc and Mharti", a fan parody of Back to the Future submitted to Channel 101. When it was taken up by [adult swim], it was retooled to make the Back to the Future elements much less overt.