History Main / EitherOrOffspring

* ''Fanfic/HalkegeniaOnline": When [[Literature/SwordArtOnline ALfheim Online]] was transported to [[LightNovel/TheFamiliarOfZero Tristain]] certain parts of its lore was made real as well: such as if two fae of different races were to have a child, the resulting child will always be the mother's race. No word on Human/Fae hybrids.

* ''LightNovel/HowARealistHeroRebuiltTheKingdom'': Interspecies relationships in the series tend to result in children being of only one parent's race: for example, Juna Domo is fully human aside from having blue hair, but her grandmother is a DraconicHumanoid "sea serpent", while her cousin Carla is a DraconicHumanoid "dragonewt" born of a dragonewt father and sea serpent mother. Pairings involving dragons are an exception to the rule, with ''three'' potential results: either a dragon egg (which is taken back to the Star Dragon Mountain Range for incubation due to the fact it can take longer than the non-dragon partner's entire life to hatch), the partner's species, or a HalfHumanHybrid race (dragonewts for standard winged dragons, sea serpents for ryuu like Naden Delal).

* In ''Webcomic/{{Precocious}}'', Bud is a Scottish fold like his mother, while his older sister is a white American shorthair like their dad.

* In ''Anime/BNABrandNewAnimal'' it's explained that beastmen of different species will produce children of one species or the other, no hybrids, and humans without the beast factor gene can't become beastmen. Which is where Michiru, a Tanuki beastman who can change her limbs into parts from other species and used to be human, comes in. [[spoiler: Though the villain turns out to be a "purebred" beastman who looks down on the other "hybrid" beastmen and is plotting their genocide.]]

* In ''ComicBook/SonicTheHedgehogArchieComics'' Jon, the son of Rob O'Hedge and Mari-An, is an Echidna, like his mom. Most other children of interspecies couples are one species or the other but follow GenderEqualsBreed.
* In ''[[ComicBook/MyLittlePonyFiendShipIsMagic My Little Pony: FIENDship is Magic]]'' uses this trope to explain why Tirek, a centaur, has a brother who looks like a completely different species. They're the offspring of an InterspeciesRomance between a centaur and a gargoyle, Tirek is a centaur like his father and Scorpan is a gargoyle like his mother.

* In ''WesternAnimation/HotelTransylvania2'', vampire Mavis and human Jonathan have a child, Dennis, and the main focus is on what he'll turn out to be. [[spoiler:He's a vampire]].

* ''Literature/TheLordOfTheRings'': Humans and Elves can reproduce with each other, and a number of such unions took place over the setting's history. However, any resulting children will be human, barring direct interventions by the [[CouncilOfAngels Valar]] who can in exceptional circumstances allow someone with both parentage to chose Elf or Human. They only ever did it for one family.

* In the systemless [[http://www.amazon.com/dp/B0040JHT06 Zodiacs]] campaign guide, it is mentioned that any child has roughly a 3 in 4 chance of being the same species as their mother.

* In ''Franchise/MassEffect'''s [[OneGenderRace monogendered]] [[GreenSkinnedSpaceBabe asari]] species, any reproductive pairing will end up with the child being asari as well. This is because asari [[BizarreAlienReproduction do not reproduce sexually like other species]], but instead use their finite control over their nervous system to [[ExoticEquipment copy part of their partner's genetic code into their daughters']], which is then carried to a full-term pregnancy as would be expected of a near-human humanoid.

* This is generally how interspecies births work in ''VideoGame/TheSims''. For example, if a werewolf and a vampire have a baby, the result is only one or the other. Glitches may result in faux-hybrids which don't function properly (missing interactions, UI, etc).
* Implied to be how families with mixed species work in ''VideoGame/KitariaFables''. The main character Nyan, who's an anthro cat, has at least a few anthro bunnies in their extended family, including their uncle, their cousin Kiki, who sells seeds in Paw Village, and their grandfather.

[[folder:Web Comics]]

* In the game ''Website/DragonCave'', in most cases the offspring of different breeds will randomly be either of the parents' breeds. The only exceptions are the handful of pairings that can actually produce a hybrid, pairings that include a holiday dragon and a non-holiday (which will only produce the non-holiday breed unless bred during its holiday season), and Bright Pinks and Frills during the time when they were retired (which would also only produce the non-Frill/Bright Pink breed).
* ''WebAnimation/{{RWBY}}'': Faunus genetics defy scientific understanding. When a Faunus and Human have a child, the offspring will be either one or the other, never a hybrid of the two; sometimes the child will initially look Human, but manifest the Faunus trait later on. Faunus' of the same type will always produce a child of their type, and a Faunus child born with one human parent will always have their Faunus parent's traits; however, the child of two different kinds of Faunus will have completely random traits; for example, if a Dog Faunus and a Cat Faunus have a child, their offspring might be a Snake Faunus.

* ''WesternAnimation/{{Wakfu}}'' invert GenderEqualsBreed with [[spoiler:Evangelyne and Sadlygrove's children]], as each kid is the same race as their opposite-sex parent. Of course, in this world "race" is a misleading concept: individuals take an appearance based on the god they identify the most with, thus it's more of a case of the children leaning toward the same religion/occupation as a parent independently of their gender.

* Some members of the four different races in ''WesternAnimation/TheLegendOfKorra'' can each [[ElementalPowers "bend" (control) a classical element]] ([[BlowYouAway Air]], [[MakingASplash Water]], [[DishingOutDirt Earth]], or [[PlayingWithFire Fire]]), but only [[TheChosenOne the Avatar]] is able to use all four elements. Children of mixed parentage can either control [[MutuallyExclusiveMagic one element]] (each), [[{{Muggle}} or none at all]].
** Best demonstrated by the children of Aang (an Avatar with Air as his native element) and Katara (a master of the Water element); who both have a non-bender son, a waterbender daughter, and an airbender son. [[spoiler:The lone son without elemental powers suddenly becomes an airbender thanks to a [[MassSuperEmpoweringEvent worldwide supernatural incident]], but this is apparently [[RandomlyGifted a coincidence]].]]
** Mako and Bolin are two brothers born to a mother and father from the Fire and Earth nations respectively, and thus Mako is a firebender and Bolin is an earthbender. Unlike the above example, there's no correlation between their sexes and elements.
* There are three types of ponies in my ''WesternAnimation/MyLittlePonyFriendshipIsMagic'': {{unicorn}}, {{pegasus}}, and earth pony. Whenever ponies of different types reproduce, they will never have an offspring who has magic from both races. They will be one or the other or, in rare cases, neither.
* In ''WesternAnimation/YoungJustice2010'', this is apparently how Martian races work. WordOfGod says that M'gann's father is a White Martian while her mother (Martian Manhunter's sister) is Green; most of her siblings are Green, but she has one White brother, [[spoiler:along with being White herself]].
* ''WesternAnimation/MODOK2021'': Of M.O.D.O.K.'s children, Lou is a normal human like their mother while Melissa is a {{Cephalothorax}} in a hover chair like their father.

* ''TabletopGame/DungeonsAndDragons'': When trens and troglodytes interbreed, the resulting eggs will hatch into either full trens or full troglodytes, with an equal chance of each.

* ''WesternAnimation/{{Wakfu}}'' invert GenderEqualsBreed with [[spoiler: Evangelyne and Sadlygrove's children]], as each kid is the same race as their opposite-sex parent. Of course, in this world "race" is a misleading concept: individuals take an appearance based on the god they identify the most with, thus it's more of a case of the children leaning toward the same religion/occupation as a parent independently of their gender.

* In ''WesternAnimation/YoungJustice,'' this is apparently how Martian races work. WordOfGod says that M'gann's father is a White Martian while her mother (Comicbook/MartianManhunter's sister) is Green; most of her siblings are Green, but she has one White brother, [[spoiler:along with being White herself]].
* ''[[WesternAnimation/MODOK2021 M.O.D.O.K.'s]]'' children, Lou is a normal human like their mother while Melissa is a {{Cephalothorax}} in a hover chair like their father.

* In ''WesternAnimation/BojackHorseman'', offspring of human/FunnyAnimal couples (or different species of animals) follow this trope. WordOfGod has confirmed that in the series' world, there are no hybrids and children of InterspeciesRomance couples will either be one species or the other.
** When Bojack Horseman [[ImagineSpot dreams]] about having a daughter with his deer ex-girlfriend Charlotte, their child is a horse. But Charlotte's real-life children with her actual (human) husband are [[GenderEqualsBreed a deer daughter and a human son]].

** There's also Bojack's [[spoiler:half-sister]] Hollyhock, who has a [[spoiler:human]] mother, but she's a horse (because [[spoiler:she and Bojack both share the same horse father, Butterscotch]]).

** Best demonstrated by the children of Aang (an Avatar with Air as his native element) and Katara (a master of the Water element); who both have a non-bender son, a water-bender daughter, and an air-bender son. [[spoiler:The lone son without elemental powers suddenly becomes an air-bender thanks to a [[MassSuperEmpoweringEvent worldwide supernatural incident]], but this is apparently [[RandomlyGifted a coincidence]].]]
** Mako and Bolin are two brothers born to a mother and father from the Fire and Earth nations respectively, and thus Mako is a fire-bender and Bolin is an earth-bender. Unlike the above example, there's no correlation between their sexes and elements.

* ''Series/{{Bewitched}}'': If you consider Samantha and her family as being part of a WitchSpecies apart from humanity, Tabitha is definitely from the same species as her witch mom. With Adam it's been played both ways.

* In the systemless [[http://www.amazon.com/dp/B0040JHT06 Zodiacs]] campaign guide, it is mentioned that any child has roughly a 3 in 4 chance of being the same species as their mother.

* ''TabletopGame/{{Eon}}'': Humans and elves can produce viable offspring, but the offspring of such a union is either elf or human depending on whether or not they inherit the life magic field that grants longevity from their elvish parent. That said, the offspring of such a union will inherit traits from their parents as any child does, so an elf with one human parent will quite likely be stockier and have more body and facial hair than one with two elvish parents, and vice versa.

* ''WebAnimation/{{RWBY}}'': When a human and a [[LittleBitBeastly Faunus]] have children, the children will be either human or Faunus of the same breed as their parent, with no hybridization. Though there is mention that occasionally it can take time for the Faunus traits to manifest. On the other hand, if two Faunus of different breeds have children, the children will be a completely random animal breed, not necessarily related to either of their parents.

* ''[[WesternAnimation/MODOK2021 M.O.D.O.K.'s]]'' children, Lou is a normal human like their mother while Melissa is a {{Cephalophorax}} in a hover chair like their father.

* In ''ComicBook/ArchieComicsSonicTheHedgehog'' Jon, the son of Rob O'Hedge and Mari-An, is an Echidna, like his mom. Most other children of interspecies couples are one species or the other but follow GenderEqualsBreed.

* ''Literature/TheLordOfTheRings'': Humans and Elves can reproduce with each other, and a number of such unions took place over the setting's history. However, no true hybrids exist, in large part due to the two species being distinct in a metaphysical, as well as biological, sense -- Elves are tied to the physical world and linger within it after death, remaining as shades in the Halls of Mandos until the world will be remade, whereas humans depart for... somewhere else, presumed to be the Timeless Halls where Eru ({{God}}) dwells, and leave the material world behind. Since no halfway point can be made between these two fates, children of Men and Elves remain in an "in-between" state for a while, but inevitably have to choose to join one species or the other, becoming either fully human or fully elven.

[[folder:Comics]]

[[folder:Film -- Animated]]

* In ''WesternAnimation/HotelTransylvania2,'' vampire Mavis and human Jonathan have a child, Dennis, and the main focus is on what he'll turn out to be. [[spoiler:He's a vampire]].

[[folder:Live Action TV]]

* ''{{TabletopGame/Eon}}'': Humans and elves can produce viable offspring, but the offspring of such a union is either elf or human depending on whether or not they inherit the life magic field that grants longevity from their elvish parent. That said, the offspring of such a union will inherit traits from their parents as any child does, so an elf with one human parent will quite likely be stockier and have more body and facial hair than one with two elvish parents, and vice versa.

[[folder:Webcomics]]

[[folder: Web Original]]

* ''WesternAnimation/{{Wakfu}}'' invert GenderEqualsBreed with [[spoiler: Evangelyne and Sadlygrove's children]], as each kid is the same race as their opposite sex parent.

* There are three types of ponies in my ''WesternAnimation/MyLittlePonyFriendshipIsMagic'': {{Unicorn}},{{Pegasus}}, and Earth ponies. Whenever ponies of different types reproduce, they will never have an offspring who has magic from both races. They will be one or the other or, in rare cases, neither.

In some works, the children of InterspeciesRomance are always, or almost always, the same species as one parent or the other. You can breed a cat and a dog, but you'll only get puppies and kittens rather than catdogs. Or, at least, if you ''do'' get a catdog, it'll be unusual and unexpected, rather than the normal standard expected result of reproduction between compatible organisms (weirdly enough). The organism's species is apparently controlled by one specific gene. This seems a bit weird genetically, but in a setting where interspecies reproduction is common it allows for recognizable species instead of having a bunch of [[HeinzHybrid catdogfishbirds]] running/swimming/flying around the place. It provides a sort of HybridOverkillAvoidance.