An author who doesn't want their authorship known will use a Pen Name. An author who wants everyone to know they don't want their authorship known will use Anonymous, or a pen name that very obviously presents itself as a pen name.
This is done to convey the impression — which may even be true — that the author would be in trouble were his or her identity known. So it's often done with controversial works, or works that wish to present themselves as such, and with exposes.
Compare Pen Name and Alan Smithee. Contrast Same Face, Different Name, where the pseudonym may not even be particularly opaque and serves largely to emphasize a Creator's Oddball. See also Reclusive Artist for artists who are secretive.
- Marvel Comics:
- Brotherhood, about the Brotherhood of Evil Mutants, was apparently written by "X". Popular opinion was that this was Howard Mackie, who revealed this to be true in November 2018.
- The Generic Comic Book is credited to "An Author, a Pencilist, an Inker, a Colorist and a Letterist." The writer was later revealed to be Steve Skeates.
- Farlaine the Goblin was originally published anonymously, but the author finally settled on a pen name "Pug Grumble" after a few years because he realized not having a name made it difficult for people to follow up on new books in the series. Also, he goes to comic conventions and more and more started requiring some sort of name before they could be given a table space.
- Bubbles (My Little Pony: Friendship is Magic): This one-shot is a widely circulated story, but its writer is unknown.
- Paradoxus (Winx Club, World of Warcraft): Being a fanfic pretty much ensures all of its authors use internet pseudonyms instead of their real names. There's the main author, Bloom_Farella, whose name includes the name of a canonical character and some random Italian surname; as well as the secondary authors: Daybreak, Popsicle, and Crowgirl. Plus Silvstardust as the official illustrator.
- Most of the Indonesian crew of the 2012 documentary The Act of Killing (retelling the 1965-66 mass killings that led to the dictatorship of Suharto) were not named in the credits to avoid reprisals. The companion film The Look of Silence also re-examines the killings through an unidentified man's tracking down of the men who murdered his brother.
- A Prussian nobleman wrote plays under the name J.E. Mand — jemand is German for "someone."
- The Bride Stripped Bare. Australian Nikki Gemmell eventually revealed her authorship.
- The Name Of This Book Is Secret and its sequels by Pseudonymous Bosch, although it's pretty much confirmed by now that he's author Raphael Simon.
- Frankenstein, on its initial publication, to hide that the author was a young woman.
- During her lifetime, Jane Austen's novels only identified the author with the words "By a Lady". Parodying this, The Two Ronnies serial "The Phantom Raspberry Blower of Old London Town" was credited to "Spike Milligan & A Gentleman" (The Gentleman being Ronnie Barker).
- The Federalist Papers were published under the pseudonym "Publius". The papers were drafted in response to the Anti-Federalist Papers, a series of parallel essays, published under the pseudonyms "Cato", "Brutus", "Centinel", and "Federal Farmer".
- The author of Girl: "Who are you?" Alien: "Er, I'm an alien." is completely anonymous. Not even so much as a pen name or username is given, as the forum the story was posted on allowed users to post without revealing their names.
- Andrew Marvell is largely remembered today for his poetry under his own name. However, he also wrote satire, some of it attacking dangerously powerful people — so that tended to appear anonymously during his lifetime.
- Before his death in 2006, Iraqi leader Saddam Hussein is believed to have written four novels, all of which were heavy in metaphor. Hussein wrote the first two under the name "He Who Wrote It," a classic way to preserve anonymity among Arabs.
- Parodied in Diary of a Wimpy Kid: Double Down. Greg has to write an author biography for school, so he picks the guy who writes the Goosebumps knockoff Spinetinglers. The author's name is obviously fake ("I.M. Spooky") and the About the Author section mentions nothing about him besides the fact that he's still working on new books. For his biography, Greg puts "???" under every section besides his name.
- Diary Of An Oxygen Thief purports to be an autobiography of an advertising executive who enjoyed emotionally abusing women, and regrets it so much that he considers himself undeserving of the very air he breathes, hence the book's title. It has a sequel, Chameleon In A Candy Store.
- Primary Colors was credited to Anonymous, with lots of speculation over who it might be, but political reporter Joe Klein was eventually outed as the author.
- The 1808 novel The Woman Of Colour was published anonymously, and its true author has yet to be discovered.
- The identity of George Kelting, star of The Television Ghost, was kept a secret during the show's run in the early 1930s. His name was only revealed in the 1986 book American Television Drama: The Experimental Years.
- In 1989, a song called "Spelling on the Stone", about the Elvis Lives myth,note was released by an unknown Elvis impersonator with no name put on the single or album, which, since the song is a first-person confession about Faking the Dead, was clearly a ruse to make people think it was Elvis himself. Despite being picked up for distribution by a major Country Music label (Curb Records) and spending some time on the Billboard charts, the song's performer has never been definitively identified (though evidence points to it being Dan Willis, who'd done some work for LS Records, the indie label that originally released the song).
- The Most Mysterious Song on the Internet, and other songs being investigated by the same people, are unintentional examples due to the information being lost.
- A mysterious 1999 document called "The Rock Critical List", with a whole bunch of mean Take That! quips aimed at several prominent music critics, circulated in music circles (mercilessly critiquing their writing styles, lifestyles and even physical appearances), with the author only identifying themselves by the jokey Pen Name JoJo Dancer, The Gay Rapper (a reference to the autobiographical Richard Pryor film Jo Jo Dancer, Your Life is Calling). Much of the intrigue was that there was only a small pool of possible suspects for JoJo Dancer's true identity, and they would probably be someone who the List's targets knew personally. Based on the writing style, suspicion quickly fell on Spin magazine staffer Charles Aaron, who was attacked in the List (for writing a positive profile of Limp Bizkit), but got off relatively easy compared to the others. Aaron has publicly denied writing it and refuses to discuss the matter, and no one else has ever claimed responsibility for being JoJo Dancer, but some former co-workers claim that Aaron admitted to them privately that he wrote it.
- Many unlicensed multicarts, and pirated versions of games typically have the company who made that bootleg go without credit, mainly to avoid lawsuits. There are several exceptions though, mainly when it comes to the cracking scene (e.g. Anthrox, Red Sector, Vision Factory, and Anthrax), and games that don't infringe on people's copyrights (e.g. Color Dreams, Open Corp., American Video Entertainment, and Idea-Tek).
- Many of the credits in Mega Man II are aliases, e.g. Inafking, Tom Pon, 2m03cm Man, Yuukichan's Papa, Fish Man, etc.
- The creator of Luna Game, a famous series of creepypasta games based on My Little Pony: Friendship is Magic, has chosen to remain anonymous. Part of this choice was to add to the game's spooky and haunted feel, and part was to dodge the backlash they knew the first game would get. (Bear in mind, it was published before My Little Pony creepypastas became a staple of the fandom, so it was pretty shocking at the time, despite it overall being pretty tame and even hokey.) They've never publicly revealed their identity, since, while they're not ashamed of having made the series, they don't want to be known as "the creator of Luna Game" forever. However, they did talk with YouTuber Izzzyzzz and give some insight for her video covering the series.
- Very little is known about the person who makes OverSimplified, including his name (he's normally referred to as "OverSimplified" the few times he refers to himself in third person).
- Vox and King Beau is a Creepypasta originally posted on /x/ that takes the format of a young woman named Vox who posts on /x/ looking for advice. The author of the story never goes by anything other than Vox or hints to the story being fictional at all.
- cool and new web comic is a parody of Homestuck by an author known as "o". There are many theories as to who the author is, to the point that the very mystery of his identity is a meme.