History Manga / Parasyte

The manga was also adapted into two live-action films in Japan in 2014 and 2015. The films also modernize the setting and are more condensed compared to the anime. A Korean live-action drama version, known as ''Parasyte: The Grey'', was released via Netflix worldwide on April 5, 2024.

The manga was also adapted into two live-action films in Japan in 2014 and 2015. The films also modernize the setting and are more condensed compared to the anime. A Korean live-action drama version, known as ''Parasyte: The Grey'', is schedule to stream via Netflix worldwide on April 5, 2024.

''Parasyte'' (Japanese: 寄生獣, ''Kiseijuu'') is a {{science fiction}} {{seinen}} {{manga}} by Creator/HitoshiIwaaki. It ran from 1988 to 1995 and is particularly famous for its usage of BodyHorror. It's kind of like ''Manga/{{Devilman}}'' [[JustForFun/XMeetsY meets]] ''Film/TheThing1982'' [[InTheStyleOf if directed by]] Creator/DavidCronenberg.

The manga was also adapted into two live-action films in Japan in 2014 and 2015. The films also modernize the setting and are more condensed compared to the anime. A Korean live-action drama version, known as ''Parasyte: The Grey'', is schedule to stream via Netflix in second quarter 2024.

Two collections of short stories set in the world of ''Parasyte'', ''Neo Parasyte f'' and ''Neo Parasyte m'', were published in 2016 and 2017. These stories occur during and after the events of ''Parasyte'', showing what became of Shinichi, Satomi, Migi and the parasites. A spinoff, ''Parasyte Reversi'' was published with 8 volumes by Moare Ohta. It center on Tatsuki Hirokawa, the only child of East Fukuyama mayor Takeshi Hirokawa, as he tries to investigate whether his father has secret links with parasites after some of his classmates were murdered by them. Storywise, it takes place simulateneously with the original manga.

Two collections of short stories set in the world of ''Parasyte'', ''Neo Parasyte f'' and ''Neo Parasyte m'', were published in 2016 and 2017. These stories occur during and after the events of ''Parasyte'', showing what became of Shinichi, Satomi, Migi and the parasites.

The manga was also adapted into two live-action films in Japan in 2014 and 2015. The films also modernize the setting and are more condensed compared to the anime.

* {{Bowdlerise}}: The scene where Migi transforms into a phallus is edited into a snake in the Tokyopop version of the Manga.

* TheChikan: Tamura is introduced dealing with one on a subway ride and tossing him off the train at a stop.

''Parasyte'' was first published in North America by Mixx (now better known as Creator/{{Tokyopop}}), which [[CulturalTranslation Americanized]] every character by changing their names (Reiko Tamura was renamed Tamara Rockford, while Migi was "Lefty" because the pages were reversed, for example), censored some sexual elements (though the graphic violence was left untouched), and did away with many Japanese cultural signifiers in the story. Publishing rights were later obtained by Del Rey, who re-released it, reverting the changes Mixx made and using a more accurate translation.

* WainscotSociety: Hirokawa's group of parasites function a lot like a mafia. Hirokawa serves as the mundane mayor of a city and establishes feeding areas where dead humans can safely be disposed of. Their status as a society is cemented by having territorial rules, which also apply to Shinchi: When a parasite kills [[spoiler:Kana]] out of town and Shinichi kills him, they let it go because the guy was clearly a dangerous fuckup operating on turf they recognized as Shinichi's, but when Shinichi kills one of their own in the dining garage, it's an act of war and Tamura has to reluctantly give the go-ahead to wax him.

* WainscotSociety: Hirokawa's group of parasites function a lot like a mafia. Hirokawa serves as the mundane mayor of a city and establishes feeding areas where dead humans can safely be disposed of. When a parasite kills [[spoiler:Kana]] out of town and Shinichi kills him, they let it go because the guy was clearly a dangerous fuckup, but when Shinichi kills one of their own in the dining garage, it's an act of war and Tamura has to reluctantly give the go-ahead to wax him.

* WeirdnessCensor: It takes a while before people other than Shinichi realize that nonhumans creatures are among them, despite the fact that, on multiple occasions, the parasites shapeshift right in front of many witnesses (such as the incident when [[ItMakesSenseInContext a pouncing lion is turned to mincemeat by a parasite]], and witnesses desperately and fearfully concoct the explanation he somehow managed to hit the lion with an explosive weapon in mid-flight despite never moving his arms. The sudden massive spike in grisly murders around the world is initially believed to be the work of an international cult.

''Parasyte'' (Japanese: 寄生獣, ''Kiseijuu'') is a {{science fiction}} {{seinen}} {{manga}} by Creator/HitoshiIwaaki. It ran from 1988 to 1995 and is particularly famous for its usage of BodyHorror. It's kind of like ''Manga/{{Devilman}}'' [[JustForFun/XMeetsY meets]] ''Film/TheThing1982''.

* CentralTheme: What makes a human a human and what makes a monster a monster? Can a human become a monster, and can a monster become human?

* FakingTheDead: That's how [[spoiler:Jaw]] manages to survive the attack from [[spoiler:Shinichi's mother parasite]]. After realizing that his opponent was going for a OneHitKill by trying solely to pierce Uda's heart, [[spoiler:Jaw changed the locations of Uda's organs and let him be hit]]. Afterwards, he just needed to wait for the perfect occasion to do a sneak attack -- his plan worked without a hitch, and the parasite was killed.]]

** The titular parasites may be sapient creatures who see their human hosts as nothing more than livestock to kill, devour, and impersonate, but they're not always ahaotic evil for it, nor are they treated as such by the story. Instead, they operate under BlueAndOrangeMorality; at best they're logical, ruthlessly pragmatic beings who only do what they do because they believe it's how they survive. Some even learn human emotions and empathy over time. In fact, the majority of outright evil characters are a handful of ordinary humans.

* SexSignalsDeath: Shimada baits a fat girl to follow him to an empty alley, where he eats her alive. The fact that [[FanDisservice the girl is seen completely naked when Shimada brutalizes her]] (while he is topless) means she was probably expecting to get laid.

But one specific worm goofs it up - he tried and failed to take over the brain of OrdinaryHighSchoolStudent Shinichi Izumi instead ends up stuck inside Shinichi's right arm. Because of this unique situation, Shinichi and the parasite, who eventually names himself Migi (meaning "right") are sharing the same body, but still possess their own individual intellects. This gives them an edge in battling the other parasites, who see Shinichi's ability to think independently as a threat. Shinichi also feels compelled to fight other parasites, who kill and eat humans as a source of food, in order to protect humanity; Migi on the other hand, like most other parasites, is incapable of emotion and only fights to preserve his and Shinichi's lives. Thus, Shinichi is forced to deal with all kinds of teenage issues while keeping a horrifying secret and having to battle against hordes of enemies who want to use him or kill him.

* CaughtWithYourPantsDown:: PlayedWith. When Migi tries to stimulate Shinichi's erection, it ''is'' Shinichi's right hand that's doing it, but he's not necessarily masturbating but it becomes an assumed excuse for a situation where Shinichi's mother barges into his room [[SorryToInterrupt without knocking]] and he has to hide Migi.

* ADateWithRosiePalms:
** Played with when Migi tries to stimulate Shinichi's erection. It is Shinichi's right hand that's doing it, but he's not necessarily masturbating.
** Becomes an assumed excuse for a situation where Shinichi's mother barges into his room [[SorryToInterrupt without knocking]] and he has to hide Migi.

* CatchAndReturn: During the military's move against the parasites, Goto catches the 16.8mm buckshot they're shooting in his parasite flesh, amd then massacres everyone in the room by launching them back.

* FanDisservice: PantyShot on a woman chopped in half. Later there's a [[ILoveTheDead necrophiliac]] and a [[ImAHumanitarian humanitarian]] moment -- at the same time. And then there's also the scene of Uragami [[ADateWithRosiePalms polishing his rocket]] when seeing a pretty girl.

* KillTheCutie: [[spoiler:Poor Kana.]]

* AluminumChristmasTrees: In Episode 21, Commander Yamagishi of the SAT fires his [[ShotgunsAreJustBetter AA-12]] from the hip with one hand. If this was any other shotgun, it would be ridiculous. But the AA-12's recoil actually is low enough [[http://www.businessinsider.com.au/11-unbelievable-weapons-that-only-america-has-2014-9#aa12-atchisson-assault-shotgun-2 that it can be fired one-handed.]]

* SurprisinglyRealisticOutcome: After the rest of the series has had superhuman battles between the parasites, [[spoiler:Uragami as a PostClimaxBoss makes a big show in targeting Shinichi and Murano -- and then gets downed in a single good punch to the face that breaks his jaw. Even without Migi's powers, not only is Shinichi's body still at peak capability, but Uragami is a mere human that isn't experienced in a direct fight. He was way out of his league besides having a knife on-hand.]]

One night, strange spores fall from the sky onto the earth. Out of them hatch weird little worms that quickly infiltrate human neighborhoods, looking for host bodies. The worms crawl or burrow their way into the head of a human host, transforming it and the brain inside. This effectively kills the victim, replacing the host's personality and intellect with that of the parasyte. These parasytes have a ravenous appetite for the flesh of the species they take over--in this case, humans.

But one specific worm goofs it up - he tried and failed to take over the brain of OrdinaryHighSchoolStudent Shinichi Izumi instead ends up stuck inside Shinichi's right arm. Because of this unique situation, Shinichi and the parasyte, who eventually names himself Migi (meaning "right") are sharing the same body, but still possess their own individual intellects. This gives them an edge in battling the other parasytes, who see Shinichi's ability to think independently as a threat. Shinichi also feels compelled to fight other parasytes, who kill and eat humans as a source of food, in order to protect humanity; Migi on the other hand, like most other parasytes, is incapable of emotion and only fights to preserve his and Shinichi's lives. Thus, Shinichi is forced to deal with all kinds of teenage issues while keeping a horrifying secret and having to battle against hordes of enemies who want to use him or kill him.

Two collections of short stories set in the world of ''Parasyte'', ''Neo Parasyte f'' and ''Neo Parasyte m'', were published in 2016 and 2017. These stories occur during and after the events of ''Parasyte'', showing what became of Shinichi, Satomi, Migi and the parasytes.

** The parasytes' blades, cutting through people cleanly with almost no resistance.

-->'''Migi''': Parasytes can change their appearance easily. Humans won't be able to catch them.\\

* AnArmAndALeg: [[spoiler:Shinichi]] loses his right arm when [[spoiler:Migi seemingly sacrifices himself to stop Gotou from killing them both]], [[SubvertedTrope but he gets better]].

* AsteroidsMonster: The Shapeshifting {{Blob Monster}}esque parasytes can separate into fairly small fragments.

** Shinichi averts this due to having to spend so much time fighting or fleeing from the parasytes [[spoiler:and it comes back to bite him big time; see BittersweetEnding]].

** [[spoiler:The parasytes' organization is broken, Hirokawa and Gotou are dead, and parasyte violence is almost nonexistent. Once again without a "natural predator", it's left unclear if humanity will render Earth completely uninhabitable one day.]]
** [[spoiler:Shinichi and Satomi are happily together, and she's now in college; however, because of all the school he missed while fighting the parasytes, Shinichi didn't go to college at the same time as Murano, and will take another year to catch up with her (but she agrees to help him study for the entrance test.) Tamura is dead, but she ultimately sacrificed her life to save her baby, which allowed Shinichi to feel emotions again. Detective Hirama assures Shinichi that if the boy is fully human, he will see that the baby is adopted by a loving family, and since Tamura assured Shinichi that he was, it's safe to assume that Tamura's last wish, that he be taken in by good humans and raised well, is coming true..]]
* BloodKnight: After the battle in volume seven, Gotou drops the civilized act and claims that he's a wild animal who only lives to fight.

** Parasytes eat humans because that's how they survive as a species, and they feel no more guilt about killing the sapient lifeforms who serve as their prey than humans do about eating livestock such as pigs and cows. Most are either incapable of emotion or don't care enough about it to try, so whenever they explain the reasons behind their actions, it's very matter-of-fact. Furthermore, each individual of the species will do anything to ensure its own survival. Migi is frequently baffled by what he sees as Shinichi's irrational human behavior and thoughts, and considers Shinichi's objection to plans he suggests--such as using his classmates as human shields in order to defeat A, or even just pickpocketing money to purchase a cab ride to safety--to be a misguided case of HonorBeforeReason.
** Shinichi very briefly goes into Blue and Orange ''insanity'' when he decides that [[spoiler:humans have no right to kill an organism just because it's harmful to humans and no right to impose human values on parasytes. He changes his mind after coming to the conclusion that all he can do is act as a human and protect humans, though at this point in his CharacterDevelopment, he pities Gotou more than hates him, and finally reluctantly finishes him off]].

* CarFu: [[spoiler:Migi tries it on Gotou to no avail.]]
* CatchAndReturn: [[spoiler:Gotou to the soldiers with the litany of bullets they fire at him.]]

** So, you remember [[spoiler:Uragami, the SerialKiller]] the police brought in to help identify parasytes? The one who escaped and disappeared during the big police raid after shooting his handler? He comes back [[spoiler:in the last chapter]].
** Earlier in the story when Migi met another parasyte that had succeeded in possessing its host, it mentions that Migi should move off of Shinichi's body and into his right hand. Migi wonders if it's really possible. [[spoiler:The BigBad Gotou turns out to be a mass of parasytes in a body, with two capable of controlling them all as the head.]]
** When Gotou escapes from city hall, he is shown to have two bullet wounds where Yamagishi and his troops shot him. [[spoiler:In the final volume, hoping it's the tiny chink in the armor he's been looking on, Shinichi stabs him there with a metal rod -- the rod was covered with poisonous pollutants, leading to Gotou's defeat.]]

* CombatTentacles: Parasytes fight by twisting into long whiplike stalks with razor-sharp blades on the end.
* CompositeCharacter: In the live-action adaptation, the parasyte known as "A" survives his first fight with Shinichi and Migi so he can take the role of the nameless parasyte who [[spoiler:killed Shinichi's mother and took over her body]].
* ContrivedCoincidence: [[spoiler:Shinichi's parents just so happen to be on vacation in the immediate vicinity of a parasyte who, thanks to a series of accidents, needs a new body. The result is that Shinichi's mother is beheaded so her body can be taken over.]]
* CoolOldLady: Mitsuyo. She takes Shinichi in after his fight with Gotou, loudly defends him from the suspicious neighbors, drinks with him, and gives him some parting words of wisdom as he leaves to finish Gotou off.
* CrazyEnoughToWork: {{Invoked}}. When [[spoiler:Migi and Shinichi split up to fight Gotou]], Migi pretty much thinks, "This is an extremely reckless strategy, but that means Gotou is unlikely to anticipate it."
* CreepyMonotone: How all the parasytes talk (except for Uda's, who he named Jaw -- he learned to talk by watching TV, so he speaks animatedly and uses slang). When a human starts speaking this way, it's a tipoff that they've been taken over.
* CripplingOverspecialization: The parasyte who [[spoiler:killed Shinichi's mother]] always goes for a OneHitKill by stabbing its enemies in the heart. When Uda's parasyte Jaw realizes this, [[spoiler:he's quick to protect Uda's heart in anticipation and behead the enemy parasyte from behind.]]

* DiagonalCut: A parasyte's organic AbsurdlySharpBlade can cut through a human so quickly and cleanly that they'll have time to get scared before they realize they're already dead.
** In Chapter 3, a parasyte performs a three hundred sixty degree CleanCut all around him, remininiscent of a helicopter blade, which causes the humans in front of him to fall to pieces right away, but the woman behind him is seemingly left standing. She raises her hands to her head and screams, only for her head and hands to belatedly separate from the rest of her.

* DiscardAndDraw: In a successful effort by Migi to save Shinichi's life, Migi sacrifices part of himself by traveling inside his body and patching up his heart; as a result, he now has to go into hibernation for a few hours each day, during which time he cannot wake up at all, which means he can't fight or use his parasyte detection sense to help Shinichi. On the plus side, this incident left Shinichi with superhuman physical capabilities at all times.

* DoubleMeaningTitle: ''Parasyte'' is titled 寄生獣 (''Kiseijū'') in the original Japanese, literally meaning "Parasitic Beasts". On the face of it, this refers to the PuppeteerParasite alien species which appears among humanity and begins to prey on humans. At the same time, however, it refers to the theme of humans being a threat to themselves and the earth through overpopulation and environmental destruction. Toward the end, the leader of the parasyte conspiracy, Takeshi Hirokawa, accuses humanity of being the real parasites by destroying the Earth, performing a TitleDrop by calling humans "parasitic beasts". However, the author states in the interview that humans' being parasites is Takeshi's opinion, not his; in fact, the author goes on to mention that perhaps all living beings on the Earth can be considered parasites from the Earth's POV, implying that the title isn't referring to one organism in particular.
* DwindlingParty: What happens to Yamagishi's unit when they go up against Gotou.
* EarnYourHappyEnding: [[spoiler:Shinichi goes through hell and back and is forced to witness several brutal, traumatizing deaths, but in the end the parasytes have pretty much stopped killing humans, and he finally gets to be with Murano.]]

* ExpositoryHairstyleChange: Shinichi has one after [[spoiler:he and Uda take down the parasyte who killed his mother.]]
* FakingTheDead: That's how [[spoiler:Jaw]] manages to survive the attack from [[spoiler:Shinichi's mother parasyte]]. After realizing that his opponent was going for a OneHitKill by trying solely to pierce Uda's heart, [[spoiler:Jaw changed the locations of Uda's organs and let him be hit]]. Afterwards, he just needed to wait for the perfect occasion to do a sneak attack -- his plan worked without a hitch, and the parasyte was killed.]]

* FeelNoPain: The parasytes are connected to the host body's nervous system so they can sense injuries and negative stimuli, but they have no psychological or physiological attachment to the discomfort they feel. As such, they can't be psychologically distressed by any sensations from injuries, nor can these sensations affect them physiologically (a large amount of pain can do all kinds of nasty things to a person like shut them down entirely). This becomes evident [[MajorInjuryUnderreaction when Yamagishi blasts away a parasyte's hand]]; he doesn't so much as blink.

* FiveRoundsRapid: Played straight, as most parasytes can ignore bullets. Subverted when [[spoiler:it actually works on Reiko, and after the humans start using high-powered shotgun ammunition]]. DoubleSubverted when [[spoiler:THIS doesn't work on Gotou]].
* ForTheEvulz: Most parasytes only commit atrocities when they ''have to'', only a few of them revel in doing it. Played straight with Uragami, a ''[[HumansAreTheRealMonsters normal human]]'' who enjoys murdering people just because he ''wants to''.

* GaiasVengeance: Reiko Tamura [[spoiler:(at least in the beginning)]] [[spoiler:and the totally human Takeshi Hirokawa]] believe the parasytes were created to cull the human population to preserve the earth.
* GoodEyesEvilEyes: A good way to tell who's a parasyte is by their emotionless gaze. Subverted a few times - some humans have the same look in their eyes as the parasytes do. There's also Miki, a parasyte who learned how to look and act genuinely human.
* GoryDiscretionShot: Used exactly once: [[spoiler:Shinichi's mother's death.]]

* HalfHumanHybrid: Shinichi becomes one when Migi uses some of his body mass to repair the stab wound caused by [[spoiler:the parasyte that took over Shinichi's mother]]. This results in advanced strength and reflexes, and also in Shinichi [[SociopathicHero seemingly becoming more emotionless for a time]].

* HappilyMarried: Shinichi and Satomi, in the ''Neo Parasyte'' story ''Migi's travels''.
* HeroicHost: Shinichi and Uda, whose parasytes weren't able were take over their brain and were thus confined to other parts of their bodies.

* HopeSpot: [[spoiler:Migi finally agrees to allow Shinichi to let Kana in on the loop about the nature of Parasytes. She dies before he's ever able to do so.]]

** Every parasyte is driven to eat humans by nature, even though Tamiya Ryoko proves that they can survive by eating the same way humans do.

* HumansAreTheRealMonsters: Some of the more socially-conscious parasytes at least believe this is the case.
* ImpostorExposingTest: The military figures out a way to use an x-ray machine to detect parasytes among humans. Before that a simpler method was devised in which you pluck a hair off the person's head -- in the case of a parasyte, the ambulatory but non-sentient cells would writhe and shrink before dying.
* ItCanThink: The first few parasytes seen are slow-witted and relatively dumb, but as the story goes on, the parasytes quickly display the ability to learn and adapt to their circumstances, not to mention prioritize their actions. This is particularly the case with Tamura, whose scientific bent allows her to anaylze situations and perform experiments [[spoiler:such as Gotou]], and even [[ApeShallNeverKillApe sacrifice other parasytes to ensure her own safety and well-being]].

** When [[spoiler:a parasyte kills and takes over Shinichi's mother]], Shinichi becomes hellbent on taking it down.
** Averted when Shinichi's beaten [[spoiler:Gotou, and the pieces of his body are trying desperately to reunite, which Migi estimates only has a 50% chance of succeeding]]. At this point in his character development Shinichi has developed empathy towards the parasytes and makes it clear that it's NothingPersonal before finishing him off, thereby also nicely averting OnceIsNotEnough because he makes ''sure'' that he's dead.
* KillingIntent: Comes up a few times; after Migi spreads some of his body into Shinichi's heart's stab wound to save his life, he gains the ability (although it doesn't seem like he's always aware that he's doing it) to give someone a terrifying DeathGlare that instantly scares the hell out of them, if not causes them to turn tail and bolt. Parasytes themselves can also send out a powerful killing intent that animals can sense keenly; birds with suddenly fly away, and even a lion is intimidated.
* KillItWithFire: Strangely averted here, as practically everything else gets used -- dismemberment, impaling, gunfire from [[FiveRoundsRapid bullets]] to shotguns, and on one occasion, ''[[ImprovisedWeapon a rock]]''. Flamethrowers are briefly considered, but rejected. [[spoiler:After Gotou has proven nigh-invulnerable to the weapons that Yamagishi and his troops had been using to great effect against other parasytes, Yamagishi's last thoughts are that maybe a flamethrower would have done the trick.]] The one time it's used [[spoiler:(Shinichi's plan to hit Gotou with a flaming spear while Migi takes off his head)]] it fails.

* LackOfEmpathy: All of the parasytes. Shinichi goes through this for a while after he's partially merged with Migi, although he's aware of it and often frustrated by it. Migi and Tamura eventually get a little better about it (mostly Tamura.)
* LastStand: The battle at city hall is this for Hirokawa's parasytes. Ironically, [[spoiler:Yamagishi and his troops -- the men who eliminated the aforementioned parasytes -- end up in a [[LastStand last stand]] of their own against Gotou]].

* ALighterShadeOfBlack: While the parasytes are ruthless killers (some of whom want to take over humanity) they're definitely much better in comparison to [[spoiler:Uragami. In fact, some of the parasytes even develop human emotions over the course of the series]].
* LosingYourHead: Shinichi to [[spoiler:Gotou's head in their first fight]]. [[NighInvulnerability Of course]], he doesn't really care.
* LovecraftianSuperpower: Guess who?

* {{Masquerade}}: The parasytes try to maintain one, but it breaks down very early. The government, meanwhile, is less about "masquerade" and more about "information control," releasing information to the public as needed to avert panic.
* MoreDakka: About ten men shoot [[spoiler:Gotou]] with assault rifles, shotguns and a grenade launcher at the same time. [[spoiler:[[NighInvulnerability He doesn't care.]] See also CatchAndReturn.]]

* NiceJobFixingItVillain: At first Kuramori refuses to help Shinichi fight the parasytes out of fear for his family. However, the parasytes associated with Tamura decide to eliminate him because of his knowledge. The attempt fails, with Kuramori's wife and daughter ending up murdered, turning Kuramori into a grieving, vengeful father and widower with nothing left to lose. Tamura chews out the parasytes responsible.
* NighInvulnerability: Gotou.
* NotMeThisTime: Uragami was caught by the police when they stumbled upon him at the scene of a parasyte meal; he doesn't deny that he's the serial killer they've been looking for, but he does loudly object to their idea that he's the culprit of this particular killing.
* OffWithHisHead: Parasytes tend to go for the head, whether they're infecting or just feeding.
* OhCrap: The parasyte who [[spoiler:took over Shinichi's mother's body]] has several during its fight against Shinichi, who is able to follow and dodge its movements.
* PaperThinDisguise: Normally averted by the parasytes, but Uda's parasyte attempts this by giving him a ridiculous jawline when he and Shinichi have to kidnap Kuramori.
* ParanoiaFuel: The police's efforts to avert full-scale public panic should the parasytes' existence become known are a recurring plot point.

** The titular parasytes may be sapient creatures who see their human hosts as nothing more than livestock to kill, devour, and impersonate, but they're not always ahaotic evil for it, nor are they treated as such by the story. Instead, they operate under BlueAndOrangeMorality; at best they're logical, ruthlessly pragmatic beings who only do what they do because they believe it's how they survive. Some even learn human emotions and empathy over time. In fact, the majority of outright evil characters are a handful of ordinary humans.
** Shinichi, the protagonist of the series, even goes as far as to call this trope into question, deciding towards the end that humans have no right to hold other species to their values. Though adjusts his view quickly to clarify that he does still have to [[spoiler:put Gotou down,]] he still lets go of any malice against the parasytes.
* ParasiteZombie: The parasytes infest a host's brain and proceed to KillAndReplace them. They're not obviously nonhuman unless they're feeding or fighting, in which case their heads turn into CombatTentacles and mouths with MoreTeethThanTheOsmondFamily.
* PlayingPossum: [[spoiler:Jaw made Shinichi's mother's parasyte think it was dead and waited before finishing it off from a sneak attack from behind when it was distracted.]]
* PoliceAreUseless: Played straight early on, when the cops are just as clueless about what's going on as the rest of the country. By the end of the series, however, they've learned all about parasytes, classified them as public enemy number one, come up with methods to differentiate them from humans, and developed tactics to kill them.

* PrecisionFStrike: A grand total of one in the anime, dropped by [[spoiler:Migi]] of all people.
** [[spoiler:This actually emphasizes two important things. Firstly, how desperately the fight against Gotou is going, and secondly that Migi is becoming increasingly human in his mannerisms, including expressing emotions like frustration and fear.]]
* PrimalFear: Shinichi can cause people to experience this by delivering a bone-chillign DeathGlare, especially when he's being threatened. It's unclear as to whether or not he's always conscious that he's even doing it.

* RadiographOfDoom: A large x-ray is used by the military to spot the parasytes in volume seven.
* RemovingTheHeadOrDestroyingTheBrain: Subverted -- taking the head clean off should kill a parasyte, but they can regenerate from most partial injuries. Going for the vital organs tends to work better.

* RiddleForTheAges: It's never revealed what exactly the parasytes are or where they came from.

* ScarsAreForever: Shinichi picks up large scars on his chest and back as a result of Migi saving his life, and a scar through his right eyebrow thanks to Gotou.
* ShapeshifterWeapon: Parasytes can transform the parts of their hosts' bodies that they've taken over (usually just the head) into blades that can shred human flesh ''faster than the eye can see''.
* ShotgunsAreJustBetter: The task force commander figures out very quickly that a shotgun blast to the heart will kill a parasyte near-instantly. A load of buckshot is also much harder for them to [[ParryingBullets deflect]] than slugs fired individually.

** The parasytes' body distortion seems to be inspired by [[http://www.doc.gold.ac.uk/~mas02fl/MSC101/Vision/Pics/EscherBondUnion2.jpg [=MC=] Escher's 'Bond Of Union']], by way of Creator/JohnCarpenter's ''Film/TheThing1982''.
** The idea of a parasyte taking over the government to some degree is most definitely inspired by ''Film/TheyLive''.

* TheSymbiote: The parasytes can be categorized as either the parasyte type (those that harm their hosts while also benefitting) or the mutualist type (those that co-exist with their hosts to mutual benefit). The parasytes that take over humans are obviously the first and can also be parasitoids if they have to find new hosts (parasatoids are different from normal parasytes in that they specifically end up killing hosts) which entails them lopping off the head and quickly taking the its place before the body dies. Migi and Jaw, who only take on a portion of the host's body, are mutualists that protect their hosts from harm while giving them enhanced abilities, and while they feed off their host's blood for nutrition, it only results in their hosts needing to take in more calories.
* TenMinuteRetirement: Kuramori emphatically decides to opt out of further investigation after witnessing a parasyte battle firsthand. He's just an ordinary human -- he has a wife and child, and the whole thing is just not his fight. [[spoiler:Little late for that. [[TheCallKnowsWhereYouLive The parasyte syndicate goes after him,]] but they flub it and kill his wife and child instead; this causes him to be thrown back into the conflict when the police question him to find out what happened.]]

* TheyLookLikeUsNow: [[spoiler:As time goes on, the parasytes become more and more human, until finally there's no obvious physical differences between them and ordinary people.]]
* TinMan: Played with: the parasytes all claim to have no emotions, but in truth it's actually more complicated. They generally lack empathy and are cold and expressionless, but some such as Gotou seem to have something akin to bloodlust. As for human emotions, many feel them, just less strongly than humans; they apparently can (with time) develop complex personalities and emotions. This is evidenced by [[spoiler:Tamura protecting her son with her life and Migi sacrificing himself for Shinichi's safety and internally thanking Shinchi for his friendship -- he even says that he's glad he didn't succeed in taking over his brain.]]
* TitleDrop: When [[spoiler:Hirokawa gives his final speech, calling humans "worms - or [[TitleDrop parasytes]]. "In the original Japanese he calls them parasitic insects (kiseichuu) and corrects himself to parasitic beasts (kiseijuu AKA the Japanese kanji).]] Unfortunately, it's not present in the well-known free scanlation.
* TooDumbToLive: [[spoiler:Kana’s final fate. She ignores Shinichi's warning against trying to detect and follow him using her "power," since in her infatuation she's convinced herself that she'll be able to tell the difference between the aura of Shinichi and another Parasyte. It turns out she can't, and when she walks in on a hostile Parasyte instead of Shinichi it impales her through the body. Since she's a baseline human in all other aspects, she has lost too much blood to be saved by ANY means by the time Shinichi finds her.]]
* TookALevelInBadass: After recovering from the stab wound that pierced his heart, Shinichi can run at what looks like more than thirty miles per hour, jump more than twelve feet high without a running start, develops SuperHearing and SuperReflexes that allow him to anticipate and dodge parasyte attacks, which are ''faster than the human eye can see''.
* ToServeMan: The parasytes have a desire to hunt and consume the species they take over, and their preferred hosts are humans (we do see one parasyte who took over a dog eating another dog). The kicker is that they can actually survive perfectly well off of a non-human diet, but (most) parasytes don't feel empathy and thus see no reason to change their lifestyles.
* TranquilFury: "Migi... handle the defense."
* TruthInTelevision: Whenever the parasytes attempt to do something like punch a hole in a wall, they will sustain serious injuries. Migi is the only exception because he's the hand itself.
* UnableToCry: Shinichi finds himself unable to shed any tears after he is turned partly parasyte by Migi, even when [[spoiler:he witnesses the death of his mother's body or when Kana is killed by a parasyte. He's finally able to cry again when he watches Tamura sacrifice her life for her son.]]
* UncannyValley: In the story, parasytes are generally indistinguishable from normal humans. However, they tend to have [[DullSurprise completely blank expressions,]] and the artwork often endows them with slightly overlarge and sharply-defined eyes that give them a sinister appearance. [[spoiler:Extremely twisted humans such as Uragami also have these eyes.]]
* TheUnreveal: As was the case in "The Thing," We never find out where the parasytes really come from (aside from outer space) or why they have such an innate killing intent for their host species. Some individual parasytes such as Tamura do ponder these things, but most don't really care since it doesn't impact their lives.
* VisualPun: Since parasytes only feed on the same species they take over, the first parasyte-dog is seen eating another dog. Which would make it ''literally'' [[CrapsackWorld a dog-eat-dog world out there]].
* VomitingCop: One of the two cops who catch Uragami at the scene of a parasyte meal can't help but throw up upon seeing the body.
* WainscotSociety: Hirokawa's group of parasytes function a lot like a mafia. Hirokawa serves as the mundane mayor of a city and establishes feeding areas where dead humans can safely be disposed of. When a parasyte kills [[spoiler:Kana]] out of town and Shinichi kills him, they let it go because the guy was clearly a dangerous fuckup, but when Shinichi kills one of their own in the dining garage, it's an act of war and Tamura has to reluctantly give the go-ahead to wax him.
* WeirdnessCensor: It takes a while before people other than Shinichi realize that nonhumans creatures are among them, despite the fact that, on multiple occasions, the parasytes shapeshift right in front of many witnesses (such as the incident when [[ItMakesSenseInContext a pouncing lion is turned to mincemeat by a parasyte]], and witnesses desperately and fearfully concoct the explanation he somehow managed to hit the lion with an explosive weapon in mid-flight despite never moving his arms. The sudden massive spike in grisly murders around the world is initially believed to be the work of an international cult.

** [[spoiler:Happens in-universe to all the parasytes after the raid on City Hall -- after their existence becomes public knowledge, virtually all attacks and sightings of them disappear. They realized that open attacks and attempts to organize against humanity is dangerous for their survival -- most adjusted their diet to eat regular human food to accomodate. It's also possible that those small few who continued to kill adapted to disguise their feedings as more conventional murders.]]

* TheWormThatWalks: [[spoiler:Gotou]] is made of several parasytes, each controlling a limb.
* XtremeKoolLetterz: Paras'''y'''te, [[Creator/{{Tokyopop}} Mixx]]'s MarketBasedTitle for ''Kiseijuu''; Mixx used it to refer to the parasytes; Del Rey used the normal spelling to refer to the creatures, but kept Mixx's title.
** The interesting thing in the original version is that there are two Japanese words for "parasite" that are used in the series. The less common one is used when referring to the creatures, but the common one is used only once, [[spoiler:when Tamura refers to humans themselves as the parasites of planet Earth.]]
** And then there's the last one when [[spoiler:Hirokawa gives his final speech, calling humans "worms -- or [[TitleDrop Parasytes]]"]]. Unfortunately, it's not present in the well-known free scanlation.
* YouAreAlreadyDead: Many humans hit by a parasyte's blade don't realize they've already been decapitated or cut to pieces, which gives them enough time to scream before they fall apart.

* RightForTheWrongReasons: How did the flatfoots finally bring in SerialKiller Uragami? They caught him ''fiddling around with the {{Gorn}} left by actual parasytes.''

* SpoilerOpening: The opening theme sequence shows most important characters in the story [[spoiler:like Reiko, Kana and Gotou]], most of whom didn't appear in the first episode. It also shows that Shinichi will lose the glasses and change his hairstyle, and hints at [[spoiler:the death of Shinichi's mother]] in episode 5, as well as [[spoiler:Shinichi's RelationshipUpgrade with Murano]] in episode 21.

[[caption-width-right:275:Click [[labelnote:here]]\\
https://static.tvtropes.org/pmwiki/pub/images/parasyte.jpg[[/labelnote]] for anime artwork.]]