The favorite relative/best friend character who appears in only a few episodes or just one VerySpecialEpisode, was never mentioned before, and is heard from never again. Often provides AnAesop, like "drunk driving is bad."

The purpose of these characters seems to be delivering the moral without having to inflict the issue on a regular. You get the 22 minutes of angst, but [[StatusQuoIsGod the writers never have to deal with it again.]] {{Long Lost Uncle Aesop}}s don't sit well with shows that have loyal and obsessive fandoms, and are incompatible with the EconomyCast.

See also CompressedVice (when the issue is inflicted on a regular for one episode), RememberTheNewGuy, NewNeighboursAsThePlotDemands.
----
!!Examples:

[[foldercontrol]]

[[folder:Anime and Manga]]
* ''SailorMoon'' did this a lot, since the characters often doubled as a VictimOfTheWeek. Was especially jarring as it was occasionally suggested the leads have trouble making friends and seemed to have no real social life outside their small group, despite meeting and getting along with people fairly quickly each episode.
* A rather extreme example: The ''DragonBall'' Jump Anime Tour Special (later broadcast online) introduced Vegeta's outcast brother Tarble, who came to Earth looking for his brother's help. The special aired in 2008, '''twelve years''' after the original anime ended.
* Kim in ''[[FistOfTheNorthStar Fist of the North Star]]'', who was Ryuken's fifth student before being expelled from his dojo, is only shown in a flashback to emphasize Kenshiro's compassion to others, and is never mentioned anywhere else in the series.
[[/folder]]

[[folder:Comic Books]]
* ComicBook/{{Superman}} comics had one with Conduit, his childhood rival Kenny Braverman, all grown up and with CIA supplied superpowers. He had never seen before in decades of Superboy stories. He's only been seen once since, in an animated episode flashback to Clark Kent's adolescence.
* José Carioca's various cousins (almost all also named José). Some of them show up more than once, but there's still some that only appear in only one story. In fact, if the cousin ''isn't'' named José, they probably aren't showing up again.
** And a [[SubvertedTrope subversion]]: Scrooge [=McDuck=] was originally meant by CarlBarks to be a one-shot character when Donald needed a rich relative for a story. [[ScroogeMcDuckUniverse We all know]] [[DuckTales how that turned out.]]
* Aside from her trademarked obsession with polka-dots, this was ''[[LittleDot Little Dot's]]'' main gimmick: a never-ending assortment of uncles and aunts, most of whom had their ''own'' all-consuming passion e.g. Uncle Smoke and [[MeaningfulName smoking]].
[[/folder]]

[[folder:Live Action TV]]
* ''FamilyTies,'' where Alex P. Keaton's alcoholic Uncle Ned (played by Tom Hanks) actually makes three appearances, but two of those are a Very Special two-part episode. [[RenamedTropes Originally]] the TropeNamer.
** ''FamilyTies'' also addressed teen pregnancy, not by inflicting it on Mallory, but by bringing in Mallory's friend we've never seen before.
** Likewise, in another famed two-parter, Alex spends 40 minutes grieving over the sudden death of his close special friend... Whatshisname. Seriously, we'd never heard of him before, or ever would again.
* Matthew Perry's appearances as "Sandy" on ''GrowingPains''.
* On ''[[{{MASH}} M*A*S*H]]'''s first-season episode 'Sometimes You Hear the Bullet', Hawkeye's happy-go-lucky best friend Tommy arrives just in time to get hit with the aforementioned noisy -- and of course fatal -- missile.
* In the episode "Lie To Me" from season two of ''BuffyTheVampireSlayer'', there is Ford, Buffy's "best friend" from her old high school in L.A. Ford is dying of a brain tumor, and bargains with Spike to be turned into a vampire in exchange for Buffy.
* ''{{Scrubs}}'' takes place in a hospital, with a constant flow of patients, a setting almost tailor-made for introducing guest stars and aesops. Of course for some lessons, the emotional impact or context appropriateness of a random patient may not work for the aesop so they'll say RememberTheNewGuy and bring in a unmentioned family member (like JD's brother) or a hospital colleague who somehow never made it on camera.
** An interesting case is the patient trapped in an MRI machine ([[FridgeLogic when she could have just crawled out of the end]]) with her face obscured. Cue the {{Aesop}} about taking chances for about the third time. Then they start dating and she appears in a later episode and they bring her into another plot and another aesop by having her work as a social worker (or similar) who deals with patients. The two episodes could have easily been written for two different characters.
*** And then she had a pill addiction, making it a threefer.
* ''LawAndOrder'' occasionally brings up old friends and colleagues of the main characters - if a big deal is made about them showing up, then it's inevitable that by the end of the episode they'll have been exposed as being corrupt, and probably a murderer as well. It happens regularly enough to make this editor wonder whether the main characters know anyone honest at all.
** Given that the prosecutor introduces most of these characters as people they worked with/went to school with...
* ''StarTrek'' is a frequent user of the trope, with examples in every series.
** Practically every second episode, the Original Series introduced us to Kirk's family, old flames, old friends from the Academy... not to mention, famously, Spock's parents, original Captain, and fiance. Oh, and Scotty's librarian love interest. Most of these people met horrible fates, and none were ever seen again.
** ''TheNextGeneration'' did the same with Picard's old friends, in episodes like "Conspiracy" and "The Chase."
** ''DeepSpaceNine'' introduced Cal Hudson, Sisko's old friend, in order to make him the leader of the outlaw Maquis. The Maquis would remain important, but Hudson would be forgotten and eventually die offscreen.
** Even halfway across the galaxy, ''{{Voyager}}'' managed to run into an old flame of B'Elanna's who would become an antagonist and then die.
** ''{{Enterprise}}'' spent an episode on Archer's loss of close friend A.G. The flashbacks in that episode were the first and last we saw of him.
* ''{{Angel}}'''s writers loved to bring in characters who had history with Angel, especially from his time as Angelus. Unfortunately, there aren't that many gaps in his backstory as established on ''{{Buffy}}''. A character Angel only met briefly can work ("Why We Fight"); a vampire he sired and apparently spent years with is another story ("Somnambulist").
** On the other hand, considering that most of what we know of Angelus's time was "wandered around murdering people for fun," it's quite easy to shoehorn experiences into there. Don't forget there's well over a ''hundred years'' of doing this.
*''{{That 70s Show}}'' episode "Eric's Friend" featured a new gay character. Even though he and Eric became good friends during the episode, he was never seen or referenced again.
* ''MightyMorphinPowerRangers'' did this sort of thing a lot- in particular, one episode featured Billy getting a girlfriend who was never seen again.
**Only one? They actually recycled that plot for Billy ''three times''.
* ''FullHouse'' had Uncle Jesse's Greek Grandpa Papouli show up, have fun with everybody, then die about midway through the episode. They mourned, the VerySpecialEpisode taught us how to cope with old people dying, and Papouli was NEVER MENTIONED AGAIN since. (I'm surprised no one here even remem...oh, screw it.)
** He had actually shown up before with his wife in an earlier episode. He was only brought back again just to deliver the VerySpecialEpisode.
** They also had an anorexia episode with D.J. similar to the ones mentioned above.
[[/folder]]

[[folder:Newspaper Comics]]
*Andy's mother has shown up only a couple times in ''FoxTrot'', usually just to play TheAce to Andy. She hasn't been seen in the strip since 1999.
[[/folder]]

[[folder:Western Animation]]
* Apart from Static and Gear, most of the good Bang Babies on ''StaticShock'' simply stuck around long enough for us to learn their Special Problem, then disappeared into the ether.
* In ''{{FamilyGuy}}'' episode "Peter, Peter, Caviar Eater", Lois' Aunt Margaritte comes to visit right at the beginning of the episode, but drops dead even before completing her first line, right there at the front door. On the commentary track, Seth [=MacFarlane=] explains that this scene was a direct parody of characters like this.
**FamilyGuy has also played this trope straight on a few occasions. Lois' brother appeared in one episode as a maniac before never being seen again. Lois' sister showed up in one episode to have a baby before never being seen again, though she at least gets occasional references in dialogue.
*AmericanDad made fun of this trope during one episode. Francine calls her sister for the purpose of exposition and the conversation eventually ends with Francine telling her sister to never bother her again unless "some plot relevant device thrusts them back together." Stan has a similar conversation with his brother in the same episode.
* The TonightSomeoneDies episode of ''CloneHigh'' introduced - and killed - Ponce de Leon (portrayed as The Fonz and voiced by Luke Perry) as JFK's inseperable best friend, despite the fact that JFK was a main character who had already appeared extensively.
* ''{{Jem}}'' did this a few times for [[VerySpecialEpisode Very Special Episodes]]. For example, Laura Holloway, who only existed in the episode "Alone Again" to get addicted to drugs and teach AnAesop.
* Cousin ''Joss'' in KimPossible. The BrokenAesop learned is that Kim isn't really a hero because she can beat super villains in her sleep, but Ron is the real hero because he's a YouSuck who sucks and would follow Kim anywhere despite his fear.
* Lampshaded in the ''SouthPark'' episode "Red Man's Greed". An unfamiliar boy named Alex Glick appears in the crowd throughout the episode expressing his concern for the fate of the town. After he delivers the {{Aesop}} at the end Stan finally asks who he is, and it's revealed that he's some guy who got to do a guest voice.
* In a ''{{Captain Planet and the Planeteers}}'' episode, Linka visits a never-before mentioned cousin who gets her hooked on drugs, and turns into an addicted zombie. Said cousin dies of an overdose by the end of the episode, driving home the anti-drug Aesop, but he spent the episode wearing a red shirt, so it could be seen coming.
* XMenEvolution featured a hacker who got into Cerebro... but is never heard of again afterwards.
**Not the best example, as he was seen in crowd shots before and after, and Rogue turned into him to escape the cops when she lost control of her powers. Admittedly, he did only have the one speaking episode. Forge is perhaps a better example, showing up in only two episodes before being completely forgotten.
* C.L.I.D.E., a [[RobotRollCall robot character]] introduced in the ''TinyToonAdventures'' episode "Elephant Issues" (specificially, the [[ThreeShorts short]] "C.L.I.D.E. and Prejudice") whose main purpose is to make the episode address racism (the antagonist, by the way, is Montana Max).
[[/folder]]

----
<<|CharactersAsDevice|>>