''Animal X'' is a lengthy series of {{yaoi|Genre}} manga by mangaka Sugimoto Ami.

Yuuji Ayukawa is a meek 27-year-old man who has never been in control of his own life. From his fiancée lecturing him about his shyness and sensitivity to his position as glorified guinea pig at Endou Chemical, Yuuji is the quintessential ExtremeDoormat.

One evening, he comes home to find that he has left a window in his room open. A wild young man who has just escaped government custody leaps out from beneath his bed and threatens to kill him. Yuuji's roommate, another in the long line of bullies Yuuji apologetically endures, bursts in...and is promptly decapitated by a fifteen-foot-tall T-rex. It turns out that Minato is a 17-year-old dinosauroid, part of a species that has long lived apart but parallel with humans, and he is capable of transforming into a reptilian killing machine under stress. ''Something'' has attracted him to Yuuji's room: Yuuji "smells like kin" and Minato is immediately overcome by an overwhelming desire to mate. From there, the story becomes the tale of various {{Ancient Conspirac|y}}ies, [[CorruptCorporateExecutive corrupt researchers and executives]], and Yuuji and Minato's evolving relationship.

And then [[MisterSeahorse Yuuji gets pregnant]].

It is probably one of the least sensational uses of {{Gender Bend|er}}ing and {{Mpreg}} since ''Literature/TheLeftHandOfDarkness''.

Currently has three series, ''Aragami no Ichizoku '', ''Daichi no Okite'', and ''Genshi Sairai'', the last of which is incomplete and on hiatus.

[[NamesTheSame Not to be confused with]] the Creator/DiscoveryChannel series about cryptozoological animals.

!!Provides Examples Of:

* ActionGirl: Despite the plot revolving around the lack of women, we get a couple in Linea and Yury.
** Of course Maya is a deconstruction. She's prone to violent and borderline-sociopathic behavior, as her BloodKnight tendencies are a reflection of [[DesperatelyLookingForAPurposeInLife the psychological problems]] she has from [[MandatoryMotherhood failing to live up to the standards of her society.]]
* AdultFear: [[spoiler:Yui's kidnapping]] is this to Yuuji and Minato.
* AllLovingHero: Deconstructed with Yuiji. Although he wins over people threatening to eat him through kindness, the emotional cost of being so forgiving puts him working alongside his own rapists. Although he gains more allies this way, there's still danger in trusting people who previously saw him as breeding stock, [[spoiler: which backfires when Shirakawa rapes him.]] Furthermore, Yuiji later reveals that he's so forgiving [[DespairEventHorizon because he's been through so much awful shit that he no longer has it in him to hate everyone who wronged him,]] making him a BrokenBird more than a straight example of this trope.
* AnArmAndALeg: [[spoiler:Minato]] loses an arm and [[EyeScream an eye]] during the fight with [[spoiler:Maya]].
* ArtificialLimbs: [[spoiler: Minato]] gets one after losing an arm, and the technology comes up later when helping an injured dinosauroid boy.
* ArrangedMarriage: Yuuji and Kyouko [[spoiler:(though it ultimately doesn't happen)]].
* BadassBookworm: Yuiji shows in-depth knowledge of medicine, archeology, politics, has a little education in Chinese, and is very badass. Often, his major contributions to the plot are directly because of his education.
* {{Bishounen}}: Minato and Yuuji.
* BlackDudeDiesFirst: Inverted with the [[spoiler: zombie marines]]. The black guy is the ONLY survivor.
* BlueAndOrangeMorality: Seems to be the case with dinosauroids (both male and female), at least where gender politics is concerned.
* BodyHorror:
** Yuuji takes manifesting female reproductive organs pretty well, but is scared of the idea of carrying a child to term.
** Later, he becomes detached and apathetic about his body as a coping mechanism for traumatic experiences. It's metaphysical BodyHorror.
** Zombie Marines, anyone? Especially since they're intelligent, and slowly dying?
** The female dinosauroid infant that Maya holds briefly. One cyclops-eye, no limbs, and protrusions that look suspiciously like tentacles. It's implied the girl died shortly after birth because of her deformities.
* BreakTheCutie: Between MorningSickness, anemia, constant [[EvenTheGuysWantHim Even The Guys Want To Violently Violate Him]], having to bear the child of the man who raped him [[spoiler:(''twice'', after his gang rape by Shen and the other men of his village is revealed to have resulted in a pregnancy)]], and both him and his family being pawns/targets in half a dozen gambits, Yuuji cannot catch a break.
** He crosses the DespairEventHorizon when he finds out [[spoiler:what happened to his first child: she was subjected to vivisection, died, and then her remains were kept on ice in a research facility]]. After that, Yuuji is quietly broken and makes remarks that show that he's reached a point where he doesn't much care if he lives or dies. He eventually comes out of his depressed state, but is left deeply traumatized by the whole thing.
* ChildByRape: [[spoiler:Yuuji's first child]] was this. And so is [[spoiler:his third, yet unborn child of still uncertain paternity]].
* CursedWithAwesome: [[LawOfInverseFertility Maya]] may be unable to [[MandatoryMotherhood fulfill the duty]] [[GenderRarityValue her society]] [[DyingRace so desperately needs]], but she has the largest dinosauroid form we've seen yet, is nigh-unbeatable in battle, [[spoiler: and MultiArmedAndDangerous.]]
* CuteLittleFangs: Minato. And how!
* DesperatelyLookingForAPurposeInLife: Turns out Maya is this, due to her inability to have children she doesn't know why she's alive and has become AxCrazy to give herself some way to be useful.
* DeusAngstMachina: By the tenth or fifteenth volume you'd be forgiven for thinking that the ''entire world'' has it in for Yuuji and Minato.
* DoubleStandardRapeMaleOnMale: {{Averted}}. Even when former rapists are EasilyForgiven due to being powerful allies, it's made clear that Minato ''never'' forgives them, and implied that Yuiji's "forgiveness" (if he gives it) is a sign/symptom of his despair.
* DyingRace: Minato's.
* FantasticRacism: Dinosauroids vs humans. One of the reasons Yuiji is so often sexually assaulted is because as a human, many dinosauroids see him as a target of scorn and an outlet for their hatred.
** Much of the third manga is about how humans are paranoid about dinosauroids due to a virus that makes them extremely aggressive. Meanwhile, the dinosauroids are getting angry at the humans for not doing anything to help them deal with the virus and for shunning them for facing an epidemic.
* GenderRarityValue: The dinosauroids obviously. The general attitude towards dinosauroid women seems to differ depending on the group. Minato's village seems to expect all women to be child-bearers, yet describe this as an honor and seem to respect the female post-menopausal dinosauroid. Shirakawa tries to be a DoggedNiceGuy and earn Yuiji's trust, once they're engaged. The group at the scientists compound are apparently Type 2, as they see themselves as "entitled" to any females of their kind, [[spoiler: but ultimately turn out to be an example of Type 1 when they follow the orders of the psychic female and her clones, describing her as an object of worship]]. Shen's village treats Yuiji well [[spoiler: at first, then it becomes clear they're losing patience and expected "her" to be polyandrous all along.]]
* {{Hermaphrodite}}: Yuuji. "It feels like you're equipped for both."
* HatePlague: A dinosauroid-only disease couples itself with this in the later stages, and the rampaging dinosauroids infected with it leads to hostility from humans and further tensions between the two species. Because the disease is ultimately lethal, both dinosauroids and humans see themselves as the victims in the resulting political conflict.
* IconicOutfit: Maya is ''always'' wearing a poncho [[spoiler: to hide her [[MultiArmedAndDangerous deformities.]]]]
* JumpingTheGenderBarrier: Yuuji and Minato are a good match, but Yuuji doesn't fall for Minato until after his transformation. He wonders if part of his heart has "become female too". See also TheMindIsThePlayThingOfTheBody.
* LawOfInverseFertility: While Yuiji is very fertile, so far we've had two female dinosauroids (four if you count the mutated infant girl and her mother who we saw only briefly) both of whom are very interested in preserving the future of their race but are unable to have children.
* LoveRedeems: [[spoiler: [[AvertedTrope No, it doesn't,]]]] Shirakawa.
** Yuiji accidentally pulls this off repeatedly, turning several enemies into allies when they fall in love with him.
* MarsNeedsWomen: Or, well, secret race of dinosaur people needs hermaphroditic hybrid.
* MateOrDie: Minato is hellbent on propagating his DyingRace.
* TheMindIsThePlaythingOfTheBody: Yuuji eventually makes references to thoughts that he, at least, identifies as coming from his male or female halves.
* MisterSeahorse: Yuuji [[spoiler:(for a total of three times now)]].
* MustNotDieAVirgin: One dinosauroid in a Chinese village asks Yuiji to sleep with his dying brother so he won't die "without knowing a woman's touch." Yuiji instead uses his medical knowledge to help save the brother's life, [[SugarWiki/FunnyMoments and is promptly propositioned by the first guy.]]
* [[NinjaPirateZombieRobot Ninja Pirate Zombie Robots]]: Police officers revived to hunt rogue dinosauroids. A (technically) zombie SWAT team. Yes. Even here, however, the series never breaks from its serious, thoughtful tone.
* TheNoseKnows: Dinosauroids all have this ability in order to detect others of their kind. It's why Yuiji is so attractive to them, as the experiments done on him make him smell like a dinosauroid female, and why nobody is ever interested in [[LawOfInverseFertility Maya]] for very long.
* NoPeriodsPeriod: Averted, naturally. Yuuji is...fully functional.
* PregnantBadass: A rare male example. Whether it's hormones or his newfound relationship with Minato, Yuuji becomes much more courageous, to the point of fully intending to take on a [[TyrannosaurusRex T-rex]] with nothing but a chainsaw.
* SexForSolace: Yuiji begins instigating sex with Minato on a regular basis when they're living in Shen's village, and the dialogue he has when propositioning him implies this trope.
* ShownTheirWork: Drumheller is a real town in Alberta, Canada, that claims to be 'The Dinosaur Capital of the World'. Even the landscapes are fairly accurate.
* TheMedic: Yuiji. It comes in handy less often, due to Minato's HealingFactor, but he ''does'' sometimes win people over by taking care of their sick and injured. The most important time his medical knowledge comes into play is when he invents an antivirus for a dinosauroid plague [[spoiler: using his daughters antibodies]], because this action kicks off the plot of ''Genshi Sairai''.
* TookALevelInBadass: Yuiji, after getting pregnant, and Linea, after uncovering her DieOrFly powers.
* UncannyValleyGirl: Maya, apparently even more so to other dinosauroids because of her "unnatural" smell.
* WomenAreDelicate: {{Averted}} yet [[DiscussedTrope discussed]]. So far several characters have talked about how women are weak and submissive, especially when comparing Yuiji to a woman for his ExtremeDoormat personality. However, thus far almost every named female character to appear is a badass in some way, including:
** Kyouko: Yuiji's [[BadassNormal completely human]] [[ArrangedMarriage fiancé]] who climbs down a drainpipe to escape captivity, and [[IWillFindYou refuses to believe her childhood friend/fiance is dead]] [[ItsNotYouItsMyEnemies until he tells her that he's safe and there's nothing she can do to help him.]]
** Maya: An AxCrazy, [[spoiler: deformed]] dinosauroid woman who's determined to collect a "wife" for her brothers and feels despair over her own inability to propagate their race.
** [[OnlyKnownByTheirNickname K=01]]: A female dinosauroid who is apparently fertile but [[HandicappedBadass too frail]] to successfully carry to term. She's [[spoiler: actually a FemmeFatale [[IllGirl using her sickness]] to manipulate an amoral scientist and uses him to create fertile and stable clones of herself, then once she has what she needs uses her psychic powers to control all the male dinosauroids around her and leads a revolt against the humans.]] Best of all? [[MagnificentBastard She gets away with it.]]
** Linea: One of Yuiji's students who initially ''appears'' to fit several stereotypes associated with the WomenAreDelicate mentality, due to having a crush on Yuiji and being a rather silly {{Fangirl}} for him. Then we learn she's the adopted daughter of the scientist above, and she goes on a few adventures with Yuiji, including rescuing him from a highly secure facility with minimal assistance. Later, she successfully evades and escapes [[spoiler: her mother's]] attempts at capturing her, [[ActionGirl learns that she's a genetically engineered super-soldier]], and single-handedly tracks down someone else involved in the conspiracy in order to get a better understanding of her new situation. Apparently, [[RealWomenDontWearDresses having a stereotypically-feminine personality]] [[AvertedTrope does not stop her]] from keeping a calm head in stressful situations and kicking ass.
** [[HiddenDepths Dr.]] [[AffablyEvil Min]] [[EvilGenius Gwen]]: [[ForScience A genius scientist whose research]] [[spoiler: produced a super-soldier]] and who successfully took over an influential research department, [[WomanScorned showing up and replacing the man who abandoned her while she was pregnant and dismissed her work years ago.]]
** Yurya: A [[spoiler: [[OurZombiesAreDifferent zombie]]-]]special-ops agent who's part of a team that goes up against dinosauroids. She's involved in a minor LoveTriangle and, despite sleeping with the wrong guy a few times, [[WomenAreWiser actually lets her love life influence her work less than the other two guys in the triangle.]]
** [[HybridPower Yui]] herself, shown to be a super-baby at only a few months old.
** In a sense, this aversion continues onto to Yuiji himself, as he becomes more assertive and learns to fight only after his transformation. See PregnantBadass above.
** Ai Lin: A minor nurse who becomes a HeroicBystander by smuggling Yui out of captivity and returning her to Minato.
* WomenAreWiser: Male characters are far more likely to react with emotion and passion when in difficult situations, whereas female characters will keep a calm head.
** Female villains like Dr. Gwen, Maya, and [[spoiler: K=01]] almost qualify as TheSociopath, they monitor their emotions so well.
** Downplayed when Yurya gets yelled at by one of her [[LoveInterest Love Interests]]. She gets upset and seeks comfort (and does go sleep with the wrong guy), but her reaction isn't as severe as the man who broke down yelling at her in the first place.
* WorthyOpponent: [[spoiler:Maya]] considers [[spoiler:Minato]] as this.
* YankTheDogsChain: [[spoiler:Not even a full chapter after rescuing Yui from her captors, Minato and Yuuji are told that 10 dinosauroid prisoners will be killed if they don't give her back. Minato grudgingly agrees that it's for the greater good, Yuuji adamantly refuses. He gets overruled.]]
* YaoiGuys: Yuuji and Minato, although Yuuji's biological reality raise the question of whether the series is, strictly speaking, "yaoi".
** Minato initially identifies Yuuji as a female (by scent) but refers to him with masculine pronouns. And though Yuuji has always been somewhat "feminine" (cooking, sewing, submissive, etc, forgive the generalizations) and [[{{Bishounen}} is very pretty]], he has lived his life and thinks of himself as a male. It's yaoi.
*** On the one hand, he always distinguishes himself from women, on the other, he doesn't consider himself and Minato to be a gay couple. "Ah, no, if that were so then we couldn't have children, could we?"
* [[YouWouldntLikeMeWhenImAngry You Wouldn't Like Me When I'm Angry]]: The dinosauroids turn into... well...''dinosaurs'' when stressed or angry, and not the sissy herbivore kind.
* YourNormalIsOurTaboo: Minato shows a few signs of this. [[GenderRarityValue Due to growing up in a culture where women are expected to have as many kids as possible,]] he didn't seem to understand why Yuiji would be upset about being pushed into sex immediately after meeting him. Fortunately, he has enough intuition not to push and to wait until Yuiji consents.