-->'''Nibblonian 1''': It's a genetic abnormality which resulted when you went back in time and performed certain actions which made you your own grandfather.\\
'''Fry''': I did do the nasty in the past-y!
--->--''WesternAnimation/{{Futurama}}''.

%% One quote is sufficient. Please place additional entries on the quotes tab.

Simply put, a StableTimeLoop where one is his own ancestor. Of course, this implies an IdenticalGrandson, and an [[TemporalParadox Ontological Paradox]] which results in a quarter of one's DNA being created from out of nowhere.

The trope namer is not an example, however. The song ''[[http://www.youtube.com/watch?v=zeIsxXDyjlc I'm My Own Grandpa]]'' by Lonzo and Oscar in 1947 is about how the singer's character became his own ''step''-grandfather through [[TangledFamilyTree complicated marriages]]. This trope is about being one's own ''biological'' ancestor.

If they're just pretending to be their grandchild, then that's MyGrandsonMyself. See also KidFromTheFuture, for more time-travel and offspring-related hijinks, and TimeTravelRomance, which could also lead to this trope.

See also GrandfatherParadox.
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!!Examples:

[[foldercontrol]]

[[folder:{{Anime}} / {{Manga}}]]
* Pierrot Bolneze in ''YakitateJapan'' was abandoned at a circus as an infant, but by Kazuma Azuma's history-changing Taima Ja-pan, he goes back to his childhood and ends up saving his mother from DeathByChildbirth. When Pierrot comes back to current time, both his parents are alive in this timeline. In this version of reality, he became a clown and was named Pierrot because his parents were so impressed with their old butler, the adult Pierrot from the future who was abandoned and raised in a circus.
* ''TsubasaReservoirChronicle'' - oh my, oh my, OH MY!! Following Cloney and C!Sakura's HeroicSacrifice, they re-incarnate ''in the past'', meet, marry and then comes the WHAM moment of the story, when they become '''the parents of R!Syaoran''', as the reader drops [[MindScrew brain dead]] at this point. Then it only gets worse as more logic is thrown of the window...
** Also creates [[YouFailBiologyForever more biological screw]] when you realize that Father, Son and Grandson [[CloningBlues all have the same DNA.]]
** [[FridgeBrilliance This all makes a weird sort of sense]] when you take into account that the BigBad of the story has been making an attempt to rewrite the basic laws of reality, screwing up everything and causing things that ''should not make sense, or are flat out impossible'' to happen.


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[[folder:Comic Books]]
* Played with, but averted, with the MarvelComics villains Kang the Conqueror and DoctorDoom. Kang, the UrExample of the ConquerorFromTheFuture, was for some time believed to be a future version of Doom, and the two worked together (and double-crossed each other) on many occasions, culminating in the ''Secret Wars'' maxiseries, in which Doom had Kang disintegrated by [[DoAnythingRobot Ultron]] (he got better with the help of a RealityWarper). Later, however, it was revealed that Kang wasn't really Doom's future incarnation. He was actually either Mister Fantastic's father or distant cousin or some such thing ([[TangledFamilyTree it's confusing]]).
** What complicates it is that Reed Richards' father and Kang are ''both'' named Nathaniel Richards, but are completely separate people. We think.
** That can be explained by the Nathaniel Richards, who is Kang, is named in honor of the creator of the utopian society on Earth he originated from, Reed Richards' father: Nathaniel Richards...who is also a time-traveler.
** Kang is a bit of a mess. There is another character, more or less a good guy, who's a future version of Kang, and there turns out to be a rather large group of Kangs, from different points of their own timeline or from paralleled realities, that cooperate and occasionally congregate for various purposes, then there's a larger group of Kang-analogs that are clearly Kang but have different faces, different genders, different species...
** It is supposed to be impossible in the Marvel universe to become our own ancestor because you can't actually travel into your own past. If you try, you end up in what will already become a different universe than the one you left (for example, Rachel Summers tried to avert the future she came from, only to eventually find out she had arrived in a different timeline).
* In ''Comicbook/{{X-Factor}}'', the longstanding question of Shatterstar's relationship with Longshot was finally resolved. [[spoiler: Due to a mystical battle, Shatterstar got blasted back to his native dimension [[AnotherDimension Mojoworld]], but [[TimeTravel in the past]]. The Spineless One scientist Arize used genetic material taken from Shatterstar to create [[ArtificialHuman Longshot]]. At a relative future point in Mojoworld's timeline, Longshot will father a child with the human mutant [[ComicBook/XMen Dazzler]]. This child will be [[HalfHumanHybrid Shatterstar]]. The infant will then be taken even further into the future, to be raised to become a gladiator and [[StableTimeLoop leading the life]] that includes his own involvement in the creation of his "father" and arranging his own upbringing.]] And we thought Cable and Rachel Summers had messed up origin stories!
* Creator/AlanMoore's [[http://www.againwiththecomics.com/2007/11/forgotten-alan-moore-chronocops.html "Chronocops"]] strip for ''[[ComicBook/TwoThousandAD 2000 AD]]'' sees the [[TimePolice time cop]] narrator arresting his partner, who attempted to marry his own grandmother as a young woman after he suffered a mental breakdown. The narrator himself ends up retiring from the TimePolice after this and marries his partner's grandmother himself. His (now former) partner says that [[GrandfatherParadox he's going to kill him]] when he gets out of jail.
* ''ComicBook/DCOneMillion'' has the series antagonist Solaris, an evil artificial intelligence, sending a computer virus back to the 20th century, which is stopped by the Justice League by building a supercomputer to contain it, thus leading to the events that caused the rise of Solaris in the 853rd century in the first place.
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[[folder:Fanfiction]]
* Referenced in ''Fanfic/KyonBigDamnHero'', with Kyon recalling someone saying he looked identical to his grandfather at that age. Given how much time-traveling he does...
** The Inuyasha fandom has a fan theory that Kagome is her own great-great-great...grandmother.

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[[folder:Film]]
* The title villain of ''{{Terminator}}'' is the most famous western case, as its travels back in time resulted in it "fathering" its own master Skynet.
** Technically, it could be said that it simply caused Skynet to develop sooner rather than being the cause of its existence altogether.
* ''Film/TimeriderTheAdventureOfLyleSwann'', where the hero went back in time and became his own great-grandfather.
* Marty [=McFly=] spends most of ''Film/BackToTheFuture'' avoiding becoming [[ParentalIncest his own father]]. He succeeds, but instead becomes his own namesake.
** This is subverted in part III where it's revealed that Marty ''did'' have a relative with his name on his father's side.
* Spoofed in ''Film/{{Detention}}''. "Ione is pregnant with herself?"
* Stanley sings the TropeNamer song in ''TheStupids''.
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[[folder:Literature]]
* Chuck Palahniuk's novel ''{{Rant}}'' - many of the major characters [[spoiler: repeatedly go back in time to become their father, grandfather, great-grandfather, etc.]] with the theory that [[spoiler: this eventually allows for an ascent into godhood via killing yourself since things without beginning have no end.]]
** Not only that, [[spoiler: the main character himself is his own [[strike: father]] [[strike: father and grandfather]]]]''[[spoiler: entire line of male ancestors.]]'' ''Lots'' of [[spoiler: time travel]] needed for that.
* Played to the extreme in the Creator/RobertAHeinlein story ''Literature/AllYouZombies'', [[spoiler: about a man who was both of his own parents. He was born a female, but was really a {{hermaphrodite}} and lost his female parts after giving birth. Then he went back in time and had sex with himself, in an attempt to save herself from that man who knocked her up and left her, then kidnapped his baby self, went back in time, and dropped it off at an orphanage. Every single significant character in the story turns out to be that one individual.]]
** [[spoiler: {{Lampshaded}} when the song "I'm My Own Grandpa" comes on the jukebox; he becomes angry and unplugs it.]]
** "Literature/ByHisBootstraps" is an example by the same author of the "milder" version described above.
** ''Literature/TimeEnoughForLove'' has a blurb on the back cover that claims this trope occurs, but it couldn't have happened in the novel, nor could it have happened off-stage, since Lazarus's arrival date in the past was after his own birth, quite intentionally (and Maureen is already pregnant with a younger sibling of Lazarus when he arrives). The blurb-writer got a few other details of the book wrong, and probably was working from a grossly simplified synopsis.
* In ''Franchise/TheHitchhikersGuideToTheGalaxy'', Zaphod Beeblebrox's father is Zaphod Beeblebrox II, his grandfather is Zaphod Beeblebrox III, etc. When asked why, he says it was an accident [[NoodleImplements involving a time machine and a prophylactic]]. His great-grandfather takes to referring to him as "Zaphod Beeblebrox the Nothingth" as an insult because of it. Though ''The Hitchhiker's Guide'' does state that becoming one's own grandparent through time travel is nothing that a significantly well-adjusted family can't deal with.
* ''Literature/TheManWhoFoldedHimself'', [[spoiler:Dan is his own mother and father. How this is possible when time travel to the past forks into an alternate reality is unclear.]]
* In a book called "The Mirror", a young woman switches bodies/eras with her grandmother, and then lives her life (in other words, she is the one who has the great romance with the grandfather, who is thought by the family to be psychic, who gives birth to her mother...). [[TimeyWimeyBall At the beginning /end of the book]], she dies as her grandmother, while her grandmother then lives the rest of her life.
* Spider Robinson's "Have You Heard The One..." features a visit to Literature/CallahansCrosstimeSaloon by a time-traveling salesman, whose plans are foiled by [[spoiler:Philip Jose Farmer's daughter Josie, who mentions that she "thinks she's going to grow up to be Mom."]]
* The first edition of ''Literature/HarryPotterAndTheChamberOfSecrets'' has Dumbledore stating that Voldemort is the "last living ancestor" of Salazar Slytherin. Among those who realized what that ''actually'' means (in context, it's easy to miss), there was some wild speculation, especially since [[spoiler:the sequel introduces time travel, although that would be a ''llloooot'' of tedious hourglass-turning]]. Of course, it was simply a mix up with "descendant". Some people use "ancestor" in a sense that includes "descendant", but it's best not to for clarity's sake.
** Possibly to prevent things like this, the movie implies that a Time-Turner can't take you back more than 24 hours at a time.
* Creator/RobertSilverberg's time-travel novel ''Up the Line'' has a character who is trying to sleep with all his female ancestors, except his mother (as he puts it, "I draw the line at abominations"). He's careful not to father any children, he is just seeking to cuckold all of his male ancestors (except his father because sleeping with his own mom would be sick).
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[[folder:Live Action TV]]
* ''Series/{{Charmed}}'': Piper Halliwell's past life, P. Baxter, was the great-grandmother of her present life. Points for being biologically possible, as the soul is the same, not the body.
* In an episode of ''Series/StarTrekDeepSpaceNine,'' Bashir wonders about this when he meets a woman on Kirk's ''Enterprise'' whose last name was that of an ancestor's, but it proved not to be true.
** PlayedForLaughs when Bashir argues that he must have sex with the woman after she invites him to her quarters, but Miles O'Brian refuses to let him be DistractedByTheSexy.
-->'''Bashir:''' I can just see the look on your face when you return to the future and [[InsaneTrollLogic find out that I never existed!]]
** Layered even further by Sisko insisting to the time police that there were no time paradoxes in play earlier in the episode.
* ''[[Series/RedDwarf Red Dwarf's]]'' Lister is his own ''father'', through time-travel shenanigans and other convoluted oddness.
* Darla sired Liam / Series/{{Angel}}, who in turn sired Drusilla. After getting staked early on ''Buffy'', Darla is resurrected as a human in the {{spinoff}} - but she still has the disease that was killing her before she became a vampire. As a last resort, Lindsey brings in Drusilla to vamp her. On having this "family tree" explained to him, Gunn has this to say:
--> "That means the granddaughter remade the grandmother. Man, somehow that weirds me out more than the whole bloodsucking thing."
* In ''Series/TheFlipsideOfDominickHide'' Dominick time travels from the future in hope of meeting the great-great-great grandfather he's heard so much about. It turns out to be a journey of self-discovery.
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[[folder:Video Games]]
* ''{{Achron}}'': The alien Grekim are able to pull this off in gameplay (see [[http://www.achrongame.com/forums/viewtopic.php?f=21&t=2903&hilit=Grekim+grandfather&start=20 here]] for directions how). It has [[AwesomeButImpractical little practical use]] though, so it doesn't happen often.
* ''VideoGame/DigimonTamersBraveTamer'' establishes that a combination of this and TimeyWimeyBall to MindScrew levels resulted in the birth of [[spoiler:Millenniumon: far in his future as [=ZeedMillenniumon=] he released Apocalymon, whose presence came to cause the existence of [[Anime/DigimonAdventure the Dark Masters]]. One of the Dark Masters was Mugendramon, who after his appparent death merged with a Chimeramon to form Millenniumon, who would go on to do horrible things, become [=ZeedMillenniumon=], et cetera.]]
** Add to that that Chimeramon was created by [[spoiler: Ken]] as a direct result of him [[spoiler:[[MoreThanMindControl having been hit by Milleniummon's dark spores]]]] years earlier. The irony being that [[spoiler: Ken]] ended up setting the events in motion that screwed up Ryo's life by TakingTheBullet for him.
* ''VideoGame/OracleOfTao'' has a version of this that doesn't involve time travel, but rather a GodInHumanForm situation, where God impregnates her mother, even though God turns out to be her true form. [[HomosexualReproduction There are so]] [[ParentalIncest many things wrong]] [[TangledFamilyTree with this]].
[[/folder]]

[[folder:Webcomics]]
* ''IrregularWebcomic'': Adam and Jamie from ''Series/MythBusters'' attempt to do this. They screw it up, becoming each other's grandfather, and therefore their own great-great-grandfathers. Which, incidentally ''does'' prove that this trope can happen, which was the whole reason they attempted this in the first place. Myth confirmed!
* ''Wicked Powered'': Taken to its natural extreme. The main character was sent back in time twice (once [[GenderBender as a woman]] and once as a man). He arrived in the same time on both occasions. The two instances met, fell in love, got married, and conceived a child. Take a guess as to who this child was. [[spoiler: Oh. And the 'aunt' he was living with was actually his pet monkey.]] And apparently, being your own parents makes you immortal. Or something.
* ''Webcomic/{{Homestuck}}'' has the most bizarre form yet. [[spoiler: John, in the present, finds a cloning station which is locked on to four people: his Nanna, Jade's Grandpa, Rose's Mom, and Dave's Bro. He clones all four of them, using paradox slime. The slime from Nanna and Grandpa is mixed together, as is the slime from Mom and Bro. From the Grandpa/Grandma slime, clones of John and Jade are created, as are Rose and Dave from Mom/Bro slime. The part where it gets weird though, is when these clone babies are sent back in time, to become the regular them.]]
** It gets worse: [[spoiler: Four "pure" clones babies are also created ... and sent back to become Nanna, Grandpa, Mom and Bro in the first place.]]
*** [[UpToEleven It gets much worse.]] [[spoiler: Since John could be considered as "fathering" all the kids AND guardians, (since he did actually physically push the button and create them) John is... his own (second?) father, his grandfather, his [[SerialEscalation half-sister's father, and her great-grandfather, his own great-grandfather, and his father-in-law + his own grandfather-in-law, if he does marry Rose. That's not counting the implications if you consider his being a "father" to Rose, Dave, Mom and Bro, which just makes it all the more convoluted.]]]]
** This also happened with [[spoiler:the trolls, with Karkat performing John's role. In this case, owing to the fact that troll parentage [[MemeticMutation sure is weird]], he also created the trolls' {{famous ancestor}}s, who are actually their decendants. The fact that he was the one who cloned them in the first place means that, by some definitions of parent, he is their collective father.]]
** And now, in the [[spoiler: Alpha Universe]], the kids and their guardians [[spoiler: switch places, but presumably keep their old biology]]. Don't ask what that does to everyone's relations.

[[/folder]]

[[folder:Western Animation]]
* A well-known example is the ''WesternAnimation/{{Futurama}}'' episode, "Roswell That Ends Well", where Fry unwittingly becomes his own grandfather by the direct expedient of doing, as he puts it, "the nasty in the past-y". Surprisingly, this actually became a major plot point in some later episodes.
** To clarify, Fry meets his grandfather, Enos, in 1947 Roswell and becomes so afraid of getting him killed (and thus not existing) that he winds up causing him to die. Later, Fry (still perplexed that he is alive) comforts the woman he believes to be his grandmother. She drunkenly propositions him, and Fry deduces that since he's still alive after accidentally killing Enos, Enos must not really have been his grandfather, and therefore she must not really be his grandmother. His logic is faulty.
** This trope is why Fry's the only one capable of saving the universe and also explains why Fry ''not'' going into the future in "Anthology of Interest" causes the universe to self-destruct. By not getting frozen, he couldn't end up becoming his own grandfather, [[TemporalParadox and thus caused a major paradox.]] [[spoiler: And by being his own grandfather, he lacks a certain brain wave making him immune to psychic forms of attack, leaving him the only one able to stop the Brainspawn, and later, the Dark Ones, from destroying the universe.]]
* In an episode of ''WesternAnimation/XiaolinShowdown'', Dojo warns Omi that by using the Sands of Time, "You can end up becoming your own grandpa."
* Averted on ''WesternAnimation/CountDuckula'', in which the character only ''claims'' he's his own father, grandfather, etc. He really means that each time he comes back from the dead, he remembers nothing and is effectively reborn with a fresh personality.
* ''FairlyOddParents'' has an example. In the [[ShowWithinAShow Crash Nebula]] episode, Wanda says that there is an episode where Crash discovers he's his own great grandfather after traveling through time.
* ''WesternAnimation/FamilyGuy'' has Stewie taking the place of his ancestor LeonardoDaVinci when he is killed by Bertram and managing to pass his own genes down before freezing himself and taking TheSlowPath back.
* In the ''IAmWeasel'' episode "My Friend, the Smart Banana", Weasel and the banana have an intellectual discussion and conclude that if you travel faster than the speed of light, you become your own grandmother.
[[/folder]]

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