History Main / CousinOliver

** Gibby's younger brother Guppy was introduced around the time that Creator/NoahMunck started puberty (Guppy's even portrayed by Noah's real-life brother Ethan) however, he's in only five episodes.

* ''ComicStrip/{{Luann}}'': Shannon. Originally just a BrattyHalfPint that was occasionally babysat by the titular character, she was then [[RetCon retconned]] into the niece of Toni, Brad's love interest. Over time she appeared more and more, to the point where now she's essentially being raised by Toni and Brad (good luck finding a Brad/Toni story since 2017 that doesn't focus mainly on Shannon) while her actual father [[ParentalNeglect hasn't been seen on-panel in years.]] In addition, she's become a regular at Luann's house as well.

** In Season Two, this was subverted with Alice's 5-year-old daughter Penny, who was certainly adorable and precocious but had considerably less screen time and significance than Jay's 12-year-old son Marty.

* Gloria on ''Series/TouchedByAnAngel'' is an unusual example - her actress Creator/ValerieBertinelli turned ''41'' just days before her character's first episode, late in Season Seven, aired. But being a newly-created angel she is a BlankSlate, requiring the guidance of series protagonist Monica in particular. By this time Monica was well-versed in the business of helping mortals, so there had to be another angel whose naivete could cause problems. (The series lasted another two seasons, with its drop in ratings likely having more to do with it being moved back to Saturday nights than audiences not accepting the character.)

* Gloria on ''Series/TouchedByAnAngel'' is an unusual example - her actress Creator/ValerieBertinelli turned ''41'' just days before her character's first episode, late in Season Seven, aired. But being a newly-created angel, she is a BlankSlate, requiring the guidance of series protagonist Monica in particular. By this time Monica was well-versed in the business of helping mortals thanks to Tess' tutelage, so there had to be another angel whose naivete in such matters could cause problems.

* Gloria on ''Series/TouchedByAnAngel'' (the Valerie Bertinelli character) is possibly the oldest example on the list.

* Chibiusa in ''Manga/SailorMoon'', came from the future and brainwashed Usagi's family into thinking she was her little sister/cousin (depending on the translation). Even if the intervention of Luna -Usagi's magic talking cat- prevents Usagi from falling under the influence of Chibiusa's magic, making her for some time the only one aware of Chibiusa's nature [[spoiler: (even if Usagi learns the whole story only much later and that Chibiusa is really her daughter from the future)]].

** With the exception of ''WesternAnimation/BeastWars'' and ''WesternAnimation/BeastMachines'', every ''Franchise/{{Transformers}}'' series has kids who tag along with the 'bots just because network people don't think like humans and believe kids would truly rather see [[WesternAnimation/TransformersPrime some kid try to impress some girl with racing]] than ''Autobots vs. Megatron and his robo-zombie horde.'' Daniel is generally considered the worst (with Kicker from ''Anime/TransformersEnergon'' a close runner-up) and Sari from ''WesternAnimation/TransformersAnimated'' was actually ''liked.'' The ''Anime/TransformersArmada'', ''WesternAnimation/TransformersPrime'', and ''[[Film/TransformersFilmSeries Bayformers]]'' kids are considered mostly harmless if not for the [[DevelopingDoomedCharacters screentime-hogging]]. In general, though, ''Transformers'' fans are JustHereForGodzilla, so every TF human begins life in Scrappy status and must pull himself/herself out.
* ''WesternAnimation/TwelveOunceMouse'' has Baby Mouse.

* The 14th season of ''Series/{{Archer}}'' added Zara to the team. She's younger, vastly more competent and very smug. Her flawless characterization did nothing to win over the fanbase, especially since with this being the final season, all she was guaranteed to do was take precious screentime away from the established cast that could have been better invested into giving them conclusive arcs.

* The Smurflings were added in the fourth season of ''WesternAnimation/TheSmurfs1981''. They are basically kid versions of the Smurfs; more accurately, Nat, Snappy and Slouchy were de-aged previous Smurfs, and Sassette was created by Gargamel like Smurfette. They also added a villainous kid, Scruple, as Gargamel's apprentice.
** Then it was Nanny Smurf, an unexplained third Smurfette from Grandpa's time and her hairy companion Snoogles introduced in the eighth season.

* ''WesternAnimation/KimPossible'': Season 4 introduced Ron's adopted Chinese younger sister Hana. Fortunately, she played an extremely small role (when she even appeared) outside of two episodes, so her existence did not significantly impact the tone of the show. It helps that both episodes are well-liked by the fanbase.

* Danny Chase in the comic book version of ''ComicBook/TeenTitans''. He was even designed to ''look'' like Cousin Oliver. Combine this with an abrasive personality, lack of codename, costume, or original powers, and he quickly became a CreatorsPet as well. In other words, Danny Chase is to the Teen Titans what Zan, Jayna, Wendy, and Marvin are to the ''{{WesternAnimation/Superfriends}}'' Justice League. At least they tried to be heroes; Chase tried to be holier-than-thou. He became Black Lantern fodder.

* Damian Wayne in the ''Franchise/{{Batman}}'' Comics, made Robin at age 10, just as [[ComicBook/Robin1993 Tim Drake]] was growing out of the tights. Lampshaded in ''ComicBook/RedRobin'' #14, where the [[ComicBook/{{Nightwing}} oldest]] and youngest of the first three Robins refer to each other as Marcia and Cindy, and lock Damian out of a file with the password "cousinoliver".
* Jason Todd. He even managed to die and grow up (in that order). Introduced as a Suspiciously Similar Substitute for Dick Grayson, who had aged out of Robin, his presence coincided with some of the lowest readership levels in Batman history. He finally got a unique origin after Crisis on Infinite Earths, but remained less popular than his predecessor, leading to his death. Of course, in death he became far more important than he had been in life and was eventually resurrected as an older teen - ironically, to replace Dick as Nightwing (as Dick was originally planned to die during Infinite Crisis). The character seems to have surpassed his origin as this trope... it just took a few decades.
* Chris Kent when he was introduced in [[Franchise/{{Superman}} Superman's Comics]]. It didn't help that [[ComicBook/Superboy1994 Kon-El]] had been killed off recently. Following the trope to the letter, he eventually caught a case of PlotRelevantAgeUp.
* Subverted with "Kid-Loki" who is just the normal Loki reincarnated as his kid self (with only his childhood memories and powers). He has avoided being TheScrappy by being just so much fun to read about (getting the best lines in any current [[ComicBook/TheMightyThor Thor]] comic), and because he is perfectly aware that he's doing things most kids shouldn't do (but, being Loki, doesn't care because he wants [[BigBrotherWorship to save Thor's life from The Serpent]]. D'awww). Plus he somehow gets the two best parts of being a KidHero--he has the youthful idealism (as much as anyone is idealistic in [[CrapsackWorld post-Civil War Marvel]], anyways), ''and'' the maturity to still actually get things done. He might be the best-liked Cousin Oliver ever for that.
* ComicBook/KittyPryde was originally one of the more famous examples in Creator/MarvelComics. She was introduced to the cast of ''ComicBook/XMen'' just as the five original X-Men were hitting their mid-20s, and after the team had been {{retool}}ed as a group of adult superheroes. She was just a teenager in her first appearance and essentially played the same AudienceSurrogate role as ComicBook/JeanGrey in the very first issue. Fans generally agree that this [[Administrivia/TropesAreTools wasn't a bad thing]]; in fact, Kitty pretty quickly became [[BreakoutCharacter one of the series' most popular and prominent characters]], and she's fondly remembered as one of Creator/ChrisClaremont's best contributions to the franchise.
* Part of the reason plans for a film adaptation of ''ComicBook/AtomicRobo'' fell through is that the Hollywood executives involved kept insisting on [[HumanFocusedAdaptation adding a "relatable" Cousin Oliver-type to serve as Robo's sidekick and youthify the story]]. The creators were stridently against the idea, knowing full well that characters like this are usually instant [[TheScrappy Scrappies]] and pointing out that ''Atomic Robo'' is a series aimed at adults which has no need for a KidAppealCharacter. They further pointed out that even if they did have a need for such a character, wouldn't kids prefer to watch a cool robot superhero over some random other kid? But [[ExecutiveMeddling the execs refused to budge]] which combined with other issues to make the creators take the rights and walk. The whole sordid affair was later parodied in the comic itself with an issue about Robo being forced to team up with a kid on a mission. He spends the entire time bitching about it, then ends the issue by deconstructing the entire idea of a KidHero and telling the kid point blank that she cannot work at Tesladyne because that would break child labor laws and be intensely unethical. Pointedly, said kid character ''does'' [[ChekhovsGunman later join Tesladyne and become a proper member of the cast]]… decades later (in-universe) when she's well into her twenties and doesn't qualify as a Cousin Oliver anymore.

[[folder:Newspaper Comics]]
* Shannon from ''ComicStrip/{{Luann}}.'' Originally just a BrattyHalfPint that was occasionally babysat by the titular character, she was then [[RetCon retconned]] into the niece of Toni, Brad's love interest. Over time she appeared more and more, to the point where now she's essentially being raised by Toni and Brad (good luck finding a Brad/Toni story since 2017 that doesn't focus mainly on Shannon) while her actual father [[ParentalNeglect hasn't been seen on-panel in years.]] In addition, she's become a regular at Luann's house as well.
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[[folder:Web Original]]
* [[https://politics.theonion.com/cousin-oliver-to-join-white-house-for-last-year-of-clin-1819565453 Parodied]] by ''Website/TheOnion''.
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* Spike Witwicky and Carly were teenagers in the first two seasons of ''WesternAnimation/TheTransformers''. Then, in [[WesternAnimation/TheTransformersTheMovie the movie]] taking place 20 years later, we're introduced to their young son Daniel.