Creator In-Joke

An in-joke is something which is only funny to those people who have a certain piece of knowledge or information. From a sociological point of view, in-jokes are used by groups to identify those who are Not-Us -- anyone who not a member of the group is not likely to get the joke. In-jokes are a stock source of humor in niche comics or shows; like jokes about computer programming that can only be understood by technicians, jokes about a film that only make sense if you listened to the director's commentary, jokes about a country's political system or culture that only citizens of that place could ever laugh at. If you are in on the joke, these can be hilarious; if you aren't, then they get irritating fast.

Some creators cannot resist putting references or jokes that only they understand into their works. Usually, these are based on events and people from their childhoods, their families, and their working environments. Sometimes these In Jokes are explained later (usually on a DVD commentary, or in an interview), but sometimes they are never explained, leading to a lot of fan speculation regarding their meaning. Unlike a regular In-Joke, sometimes the only person who knows what a particular reference means (at least originally) is the creator who added it.

Film

 * The film 2010 features a cover of Time magazine with the American president and Soviet premier. The former is Arthur C. Clarke, and the latter is Stanley Kubrick.
 * The phrase "Poopy Trim", from Kevin Smith's films.
 * Everything John Landis has directed, be it a film, a music video, or a TV commercial, has included the line "See You Next Wednesday."
 * George Lucas has somehow managed to work "THX 1138" (if only the numbers or letters) into everything he's ever done.
 * Sam Raimi puts the same car - a 1973 Olds Delta Royale, referred to as "the classic" - in almost all of his films.
 * In Super Troopers, the name of one of the Local Cops is Rando, which was something the writers called people they didn't know "randoms" during college. Not a huge injoke (as calling people randoms has been around for the last 10 years or so), but one nonetheless.
 * Steven Spielberg had hired go-motion expert Phil Tippett to do the Jurassic Park dinosaurs. Then ILM did an awesome demo of computer-generated dinos. The exchange when Spielberg showed Tippett said demo ("You're out of a job", "Don't you mean extinct?") became a dialogue in the movie.

Literature

 * When authors Tim Powers and James Blaylock were in college together, they invented a fake poet named "William Ashbless" to satirize the quality of their college's literary magazine. He ended up appearing as a character in both of their novels, entirely independently.

Live Action TV

 * "Tim and Eric Awesome Show, Great Job!": The word "chippy", which gets used a lot, comes from some weird foreign porn Tim and Eric once saw.
 * From Lost, the song "You All Everybody" and its only known lyrics ("you all everybody, acting like these stupid people wearing expensive clothes") came from an inside joke among the writers. One of them had seen someone use the phrase on a talk show many years earlier.
 * "Geronimo Jackson" is a band that is mentioned several times throughout the series. Showrunners Damon Lindelof and Carlton Cuse swear the band was a legitimate one from the 70s that no one remembers, but the pair are known for making outrageous claims and jokes. However, they are unusually adamant that Geronimo Jackson was a real band. Several independent "investigations" (searches of music databases, copyright libraries, etc) have turned up no evidence Geronimo Jackson ever existed.
 * The X-Files loved this one:
 * Chris Carter's best friend as a child was called Fox and his mother's maiden name is Mulder.
 * Various other characters are also named after people the writers knew.
 * Almost every time a date or number is mentioned it has some kind of significance (most commonly 1013/October 13th, Chris Carter's birthday, or 1121/November 21, his wife's). They even subverted it once by using the same number about five times in a single season - the number was completely meaningless but by this point fans had been trained to look obsessively for the significance.
 * Desperate Housewives 5th season finale episode "If It's Only In Your Head". Lynette is told she's pregnant and says "Are you sure it's not cancer?" This was based on creator Marc Cherry's personal experience: when his mother was told by doctors in in the early 80's that she was either pregnant or had cancer, she said "God, I hope it's cancer."
 * Bree's immediate response to learning that her son is gay is the same as Cherry's mother: "I'd love you even if you were a murderer."
 * The Mighty Boosh was named after something once said by a childhood friend of Noel Fielding (Vince): upon seeing the large curly hairstyle sported by Michael Fielding (Naboo) at the time, the foreign-accented childhood friend exclaimed "You've got a mighty bush!"
 * Angel: The "Astronauts versus Cavemen" debate in the fifth season episode "A Hole In The World" is funny enough as it is, but it was based on a real argument Joss Whedon started in the writers room that got way out of hand. He just wrote it on the chalkboard and came in later to find that the argument had effectively killed any work getting done.
 * Roughly half the characters in Monty Python's Flying Circus were named Arthur, Ken, or Eric.
 * In Lexx, Xev's home planet B3K took its name from the production company's Halifax postal code.
 * In the original proposal for Star Trek the Original Series that Roddenberry submitted to MGM in 1964, the Enterprise was to be commanded by Robert M. April. The name also turned up in two episodes of Have Gun Will Travel that Roddenberry wrote in The Fifties.

Music

 * The band Jimmy Eat World was named after an in-joke from their childhood: "The band's name came from a crayon drawing made after an incident between Linton's younger brothers, Jim and Ed, who fought frequently. Jim usually won, but Ed got his revenge by drawing a picture of Jim shoving the Earth into his mouth; the picture bore the caption "Jimmy eat world".
 * Nickelback was named after what one of the guys from the band said when he worked at Starbucks: "Here's your nickel back."
 * Folk singer-songwriter John Stewart included quotes from someone named Oliver Makin in the liner notes of two of his albums (Sunstorm, Wingless Angels). Makin was supposedly "a poet from Kansas who died in 1909", but Stewart fans haven't been able to locate any of Makin's works. The fact that the quotes conveniently just happen to include Title Drops for the albums in question pretty much confirms that Makin=Stewart.
 * Beginning with 1990s Under The Red Sky, Bob Dylan has credited himself as "Jack Frost" whenever he's produced one of his own albums.
 * Elton John was fond of his 1980's Camp Gay pseudonym, "Lord Choc Ice", and it appears in many manifestations. An instrumental B side was called "Lord Choc Ice Goes Mental", he credits his co-writing credit for the Cher co-written Leather Jackets song "Don't Trust That Woman" to "Cher/Lady Choc Ice" (he was upset that Cher wanted first billing, and tried to upstage her for revenge), he credits "Lady Choc Ice" as an "inspiration" in Leather Jackets 's liner notes, and "Lord Choc Ice" is billed as "director" on the closing clapperboard in his "I'm Still Standing" video. He was known to substitute "foreign guy" in the line "Susie went and left me for some foreign guy" in "Crocodile Rock" with "...Choc Ice guy" in his 1982 concerts.

Video Games

 * In Doom, the cheat code iddqd was named after a fraternity one of the developers formed in college.
 * Almost every Capcom franchise has included a character named Joe. From the more well-known Viewtiful Joe and the Mega Man series' Sniper Joe, there's been one in Street Fighter, Phoenix Wright, Bionic Commando and Lost Planet.
 * Some of the Halo games, especially the first one, contained a ton of Shout-Out references to Bungie's older title Marathon which effortlessly go unnoticed by those who had never played their older games.
 * Bungie also finds a way to put the number 7 in every Halo game.
 * In "Orange Lights", the tie-in comic book for The Conduit, the mailing address for Conspiracy Theorist Gordon Wells is actually the address of developer High Voltage Software.
 * One of the developers of EV Nova put his ex-boss in the game ... as a cargo drone with the subtitle "Incompetent".

Web Comics

 * From Its Walky, Walky's catchphrase "Wiigii" was inspired by a typo of the author's when he was trying to type "Woo hoo" and his right hand was off to the left.
 * The "You call this a X?" from Romantically Apocalyptic.
 * Homestuck recycles a lot of characters and themes from Andrew's more obscure work. For instance Gamzee  is partially based off his little known and orphaned graphic novel series, Whistles. The Kids and the flavor of Homestuck in general comes from what Andrew described as an idea that never left the launching pad of magical kids learning how to focus their powers and taking the piss out of it. The characters on the pages on Rose's wall are the concept art from that series. Likewise there is a poster in Dave's room of two robot rappers, they were at one point planned to be minor characters and have a rap music album based on them, but it also never came to fruition.

Web Original

 * "Homestar Runner": The phrase "Kick it out, Behan" was something the creator's Mom said at track meets when he was a kid.
 * A lot of things in Homestar Runner are creator in-jokes-- including the main character's name (see Gretzky Has the Ball for the explanation).

Western Animation

 * "A113" is an inside joke amongst a number of animators who graduated from the California Institute for the Arts; it's the classroom number where animation classes were held. See the other Wiki for a listing of some of the references.
 * The Venture Brothers: Dean calls Orpheus's pendant a "Dracula trophy". The phrase was originally something overheard during childhood by one of the show's creators, and it stuck.
 * "Jalapena" as an exclamation in Disney's Gargoyles. Keith David had known someone who used it that way, and improvised during a recording session. It stuck.
 * Apparently, a lot of the gibberish Stitch says in Lilo and Stitch is things like this, only garbled. One phrase is the name of an animator's wife, the other one is a restaurant near the studio.
 * Futurama prefers Al Gore as a constant source of humor for several reasons. Back when the show was new, people thought he was humorless, not knowing that his daughter writes for the show, and she had to get it from somewhere.
 * A subtle one from Futurama- Leela is upset and tears one half of a Kleenex to wipe her tears away. On the DVD commentary, they said that everyone assumed it was a joke because of her one eye, but the writers were referencing that they (the writers) would all use one half of the Kleenex to save money.
 * Captain Robert T. April in the Star Trek the Animated Series episode "The Counter-Clock Incident". In the original proposal for Star Trek the Original Series that Roddenberry submitted to MGM in 1964, the Enterprise was to be commanded by Robert M. April.