[[quoteright:197:http://static.tvtropes.org/pmwiki/pub/images/fb36f8bab7a808e7f06a7384b6098d00.jpg]]
[[caption-width-right:197:From bottom to top: Alice Fuji, Gokiburi and Yoriko Tajima]]
Alice Fuji does not have a fun life. She's spent the last few years being tormented and abused by her drunken uncle, whilst her unusual mental disorder and dearth of social skills have led to poor grades and a complete lack of friends at school. Then a mysterious assassin kills her uncle, press-gangs her as his apprentice, and subjects her to TrainingFromHell for a few weeks before trying to kill her when her recruitment application falls through. Now she's got an ever-increasing price on her head as she fends off one murderous, arthropod-themed lunatic after another, and the only allies she can turn to are the ''slightly less'' murderous arthropod-themed lunatics.

A manga written by Shinya Murata since 2009 and published on Gangan JOKER, ''Arachnid'' provides an unusual take on the standard shonen FightingSeries, with an interestingly deranged cast and a wide variety of exotic fighting styles. It also has a spinoff prequel named ''Caterpillar'', which focuses on an assassin named Imomushi who has her own troubles within the Organization a year before Alice became involved.

There's a character page [[Characters/{{Arachnid}} here.]]

Not to be confused with the 2001 spanish horror film ''Arachnid''. Also, for Murata's other takes on people fighting with animal abilities, see ''Vaia'n Maiden'' and ''Killing Bites''. Yū Sasuga's ''Manga/TerraforMARS'' also deals with this concept.
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!!'''Arachnid and Caterpillar contain examples of:'''
* AcademyOfAdventure: A polite way to describe Alice's school. A less polite (though somewhat more accurate) description would be 'death-trap crawling with murderous psychos'. The trope is enforced by the Organization boss, who requires the assassins to fight each other and kill Alice while inside the school. There's even a large incinerator in there to dispose of anyone killed in this bloodbath.
* ActionGirl: Alice and virtually any other female assassin.
* AerithAndBob: A girl named Alice and a bunch of people with fake names and who are codenamed after insects.
* AlwaysABiggerFish: The narrative exposition on paraponera clavata ants (aka bullet ants) in ''Caterpillar'' states they're so danguerous a group of army ants would avoid fighting a single one of them. The exposition on dinoponera ants in ''Arachnid'' is practically copy-pasted, except the paraponeras are the ones fleeing.
* AnimalMotifs: ...or rather, an insect motif, each for every assassin. Alice, however, gets a handful of different spider species motifs for the [[NewPowersAsThePlotDemands sake]] [[CrazyPrepared of versatility]].
* AllMenArePerverts: With or without the Queen's Rule brainwashing, few men in the story aren't always harassing women and [[AllMenAreRapists trying to rape them.]]
* AlmightyJanitor: [[CleanupCrew Shidemushi]] seems to be one.
* AssholeVictim: Alice's uncle in the very first chapter.
* AttemptedRape: Alice from her uncle in the very first chapter, and then Oki from Hibiki's thugs in Chapter 12. Gets much worse later, when the the entire student body of Alice's school gets brainwashed into raping people.
* {{Badass}}:
** BadassCreed: Alice's "kill before being killed" motto.
** LittleMissBadass: Alice, Oki, Kabutomushi, Geji, Dinoponera, Hanakamakiri and also Imomushi in her childhood.
** TookALevelInBadass: Alice every now and then.
* BatterUp: In chapter 12, some of the people working for Hibiki are holding Nail Bats. It's rather amusing that one of them has a ''[[GolfClubbing Nail Golf Club]]''. Even more amusing when Alice swings it at his face.
* BewareMyStingerTail: Sasori turns out to have a long mechanical scorpion tail attached to her back. [[{{Hammerspace}} How was she even hiding that, anyway?]]
* BigBad: "Army Ant" Sara Kurokawa claims she's the boss of the Organization. [[spoiler:But she is a decoy who follows ''Kuramoto's'' orders. And Kuramoto isn't the boss either]]. "Swallowtail Butterfly" Yanagi Akiho fills this role in the prequel.
* BladeBelowTheShoulder: Dinoponera has extendable needles inside her gauntlets, which have the immensely painful effect of her namesake's sting. Paraponera and Suzume Bachi also use this weapon type.
* BladeOnAStick: Kabutomushi wields a halberd with enough strength to shove people far away and make craters on the ground.
* BladeRun: Dinoponera sits on Kabutomushi's halberd when Kabuto first tries to attack her, then hangs on it to avoid being smashed into the ceiling. Later she also walks on the halberd's pole, too.
* BlandNameProduct: [[Franchise/KamenRider Kahen Rider]]. i.e., Transforming Rider instead of Masked Rider. Later on, [[Franchise/SailorMoon "Sailor-Force"]] is shown.
* BluntYes: Hibiki when Alice asks if he had a [[HoYay "deep relationship"]] with Kumo. Oki then bluntly asks if he is gay. [[VerbalBackspace He confirms it but then he backpedals.]]
* BottomlessMagazines: There's no concern in-story about whether there is a limit on the thread from Alice's Kumoito.
* {{Bowdlerise}}: The magazine version of Chapter 51 had a scene about how Sasori murdered her own parents, [[{{Gorn}} tearing them open and leaving the organs exposed.]] This got blacked out in Volume 11. Volume 12 has a case of NoSwastikas on chapter 55 where the symbol is gone from Hitler's uniform when he is briefly used to illustrate the idea of charismatic brainwashing.
* BrainwashedAndCrazy: At one point Oki is controlled by Digger Wasp, who gives her a dominatrix outfit and has her believe he is Alice. Oki doesn't seem to notice [[NotHimself how unusual]] "Alice"'s orders (such as torturing her friend Yoriko) are and gladly follows them while not actually being any crazier than she already is. Meanwhile, Sara leads and spreads mindless zombie-like students around for them to overpower and rape her enemies.
* TheBrute: "Sand Cricket" Riokku.
* TheBully: Yoriko is terribly cruel to Alice in the early chapters, to the point Alice considers killing her, but after the first encounter with Sasori, Yoriko has to keep Alice with her for protection and the two begin to get along.
* CarnivalOfKillers: Alice has a price on her head which increases as the assassins after her kill each other.
* CatchPhrase: When her life's in danger, Alice says she can only kill to survive.
* CharacterizationMarchesOn: When Dinoponera is first seen wandering around Alice's school, she looks [[EmotionlessGirl rather quiet and serious]], but then her stoic look from the [[http://www.iibq.com/comic/82012133790/viewcomic216801/?p=36&s=1 last panel of chapter 35]] [[{{Retcon}} became a smug grin]] on the Volume 7 release and suddenly she's all smiles.
* CharlesAtlasSuperpower: Everybody in this series is a "perfectly ordinary" human. You may need to remind yourself of this ''repeatedly''.
* ChekhovsGag: When Alice is feeling bad about being all hurt and bandaged up with an eyepatch, Yoriko and Oki tell her [[BandageBabe she looks stylish and cute.]] [[spoiler:Sara was introduced at around the same time. Later it is shown she does have a right eye and wears her eyepatch as part of an EvilMakeover. Subverted in that the circumstances of that reveal are ''far'' from funny]].
* ChekhovsGun: Oki is able to secrete oil as an evasion ability. Much later Kabutomushi explains she taught her to subtly do it when in trouble to leave a trail behind her for Kabuto to follow.
* CheshireCatGrin: "Scorpion" Sasori.
* ChildSoldier: Some characters are shown to have been trained by the Organization since they were small. Among them, Dinoponera was the [[ImprobableAge toddler]] doing mercenary work in war zones.
* CrazyPrepared: Alice, courtesy of her DisabilitySuperpower which is very befitting for a spider-themed string user.
** Amenbo knows how to inflate like a balloon to avoid drowning. It comes out of nowhere and the story doesn't explain how it fits her Water Strider motif (those bugs collect air on their hair if they need to float back to the surface).
** Kabutomushi can survive even seemingly lethal attacks to the heart thanks to her implanted exoskeleton armor.
** Being an experienced mercenary, Paraponera gives Imomushi a lot of trouble.
** Dinoponera's "Concentration Driving Force" ability gives her heightened senses comparable to Alice's. And while it is mentioned Alice's senses can't save her from sufficiently fast attacks, Dinoponera is agile enough to avoid practically anything.
* CreepyCentipedes: "Caterpillar" Imomushi, "Centipede" Mudake and "House Centipede" Geji.
* CreepyCockroach: Oki is creepy in a perverted kind of way.
* CuteAndPsycho: Most of the girls in the series.
* CuteBruiser: Oki, Kabutomushi, Geji and Dinoponera. Alice has her moments, but she mostly uses [[RazorFloss string tricks]] to fight.
* DamselInDistress: Early on, Oki fakes kidnapping Yoriko to bait Alice. But later Yori is captured by the Sand and Digger Wasps to be tortured by a brainwashed Oki. She tries to stay out of Alice's fight against Dinoponera, but Dinoponera jumps behind her anyway to get a reaction from Alice. [[spoiler:When Alice reunites with her later, Yori is attacked by Sasori.]]
* DarkSkinnedBlond: Riokku and Dinoponera.
* DarkestHour: Chapter 61. [[spoiler:Yoriko has been killed and practically everyone has been captured by the student mob or is missing. And Kuramoto began the mind control proccess on Alice, who still doesn't have a clue of her true intentions]].
* DeathSeeker: [[spoiler:Kumo trains Alice so she could kill him.]]
* DefeatEqualsFriendship: Oki is brought along by Alice after being defeated. It helps that Oki turned out to not have kidnapped Yori and just wanted [[PsychoLesbian to make Alice her slave instead of killing her]].
* DeerInTheHeadlights: Alice is shocked when Kumo tries to kill her at the beginning, but then she jumps to chomp his neck off. She later becomes feared for being able to avoid being completely frozen even in such dire situations.
* DecoyProtagonist: [[spoiler:You know that cool looking assassin that keeps Alice in his house? Alice kills him at the end of the first volume.]]
* DisabilitySuperpower: Alice's "Congenital Excessive Concentration", which causes her to single-mindedly concentrate on the most inconvenient things. With training, though, it allows her to enter a kind of HyperAwareness state and formulate battle strategies in seconds, and serves as arguably her greatest weapon.
* DisappearedDad: Alice has been told that her father died before she was born, but Kirigirisu reveals that he's actually alive. The father turns out to be [[spoiler:Suzume Bachi]].
* TheDragon: Suzume Bachi to the Organization boss, Sara Kurokawa. [[spoiler:But she turns out to be a decoy who serves Kuramoto. And Kuramoto is not be the real boss, either]]...
* DynamicEntry: Hibiki is fond of arriving from out of nowhere [[ConvenientlyTimedAttackFromBehind with a Rider Kick]]. Later he gets on the receiving end of Oki's dropkick.
* EnfantTerrible: Digger Wasp.
* EvilAllAlong: [[spoiler:Kuramoto spends most of the story being friendly to Alice, but turns out to be the mastermind behind the Arachnid Hunt]].
* ExoticEyeDesigns: Alice's pupils and Dinoponera's irises ripple when they concentrate. Sometimes they get both effects at once when they're [[DeathGlare angry enough]].
* EyepatchOfPower: Sara wears one over her right eye. Alice wore one while recovering from the battle with Hibiki, but then she looked cute rather than powerful.
* EyesAlwaysShut: Kamakiri acts like this before attacking Alice.
* TheFaceless: Alice's mother during flashbacks, until chapter 48.
* FlashStep: The faster characters frequently [[OffscreenTeleportation appear out of nowhere]] [[NoIAmBehindYou behind each other]]. [[BadassBack And they usually look away from the target,]] [[RuleOfCool just to look cool.]] They do have ''insect'' motifs, after all. It's later exaggerated in chapter 48, in which [[spoiler:Alice practically teleports around Dinoponera, who insists in trying to hit Alice from behind]].
* ForeheadOfDoom: Yoriko's hairstyle.
* GoombaStomp: Dinoponera at one point almost impales Hikibi's head, but is distracted when she notices Alice is on the floor above her and just stomps Hibiki instead.
* GratuitousForeignLanguage: Dinoponera sometimes speaks in thai.
* GunsAreWorthless: Some characters do use guns, but soon forget about them as focus is shifted to the assassins' weird insect-themed abilities and weapons.
* HairAntennae: Oki, as part of her cockroach theme. They even move while detecting movements around her. Oddly enough, she spontaneously gained those antennae just by identifying with a cockroach she saw back when she was an abandoned baby in a thrashed house.
* {{Hammerspace}}: Kabutomushi hides her Kabuto Horn halberd folded in half under her shirt, but it's still far too big for it to make much sense. Then there's Geji who hits Oki with a heavy filled sock that she was still wearing on the previous page. And also Sasori, who hides a scorpion tail larger than herself under her coat. Hanakamakiri often pulls her scythes from out of nowhere, too.
* HappinessInSlavery: Oki, after her HeelFaceTurn. It helps that Alice isn't remotely interested in having a slave, and just treats her as a friend instead. [[spoiler:Sara also feels this way about Kuramoto.]]
* HardWorkHardlyWorks: Having fought alone in wars during her whole life, Dinoponera expected to find a kindred spirit in Alice, but becomes enraged upon finding out she only recently became an assassin and despite this was able to master her ability in a couple of weeks.
* HellBentForLeather: For whatever reason Anabachi dresses Goki in a {{stripperiffic}} dominatrix costume after brainwashing her. [[http://arachnid-manga.wikia.com/wiki/File:Kabutomushi_and_Geji,_Fuji_Alice.jpg A bonus poster]] features Alice and Geji in their own bondage getups, plus an unamused Kabutomushi in the background, if you ever wondered what they'd look like in those duds.
* HeelFaceTurn: 'Cockroach' Oki, the PsychoLesbian assassin, would be the most obvious example (and overlaps somewhat with HighHeelFaceTurn), though Yori, the AlphaBitch who befriends Alice after the latter saves her life, serves as a less extreme case.
* HoistByHisOwnPetard: How Alice has killed some of the assassins thus far; [[spoiler: Kamakiri (Praying Mantis) slits his throat with his scythes, Amenbo (Water Strider) is held underwater and drowned.]]
** [[spoiler:Water Strider]] [[BalloonBelly held long enough underwater]] for help to arrive.
** Despite her best efforts to defeat Alice, [[spoiler:Dinoponera]] still gets tangled up and forced to stab her own leg.
* HotSpringsEpisode: The Febuary 2015 crossover between ''Arachnid'', ''Caterpillar'' and ''Killing Bites''.
* HyperAwareness: Alice, Oki, Sasori and Dinoponera have their own ways of feeling the environment around them and instantly countering any attacks.
* IJustWantToHaveFriends: Alice has been lonely and shunned by people, Oki doesn't seem completely ok with being alone and hated, and Dinoponera, who also grew alone, would like to meet someone she can symphatize with even though she's too deranged and picky.
* IKnowMortalKombat: Hibiki based his fighting style on the [[Franchise/KamenRider "Kahen Rider"]] series, training until he made reliable techniques out of the show's ideas. Riokku, on the other hand, took from that show an idea of surviving through brute force alone.
* IdiosyncraticEpisodeNaming: Chapters are named after dialogue or monologues [[TitleDrop said in them.]]
* IdiotBall: Alice comes to school on the day of the Arachnid Hunt completely unprepared, despite knowing from Sasori that something was going to happen on that day. Ironically, killing Alice while ''inside'' the school is a rule of their contest.
* ImpaledWithExtremePrejudice: Dinoponera repeatedly impales people not necessarily to kill, but to have fun watching them scream because of her stings' [[ToThePain "24 to 48 hours of great pain"]] venom. [[spoiler:Alice gets stabbed all over her arms, legs and butt because Dinoponera was that much pissed off at the time.]]
* [[ImplacableMan Implacable Woman]]: Dinoponera steamrolls everyone on her way to meet Alice, completely [[NoSell unharmed by anything she couldn't block or dodge.]]
* ImprobableWeaponUser: If an Organization assassin uses a weapon, it'll be an extremely weird one. Alice's WeaponOfChoice, for instance, is the "Kumoito", or "Spider's Thread", a length of spider-silk with a hooked blade on the end that works rather like a cross between RazorFloss and a GrapplingHookPistol.
* ImOkay: Only five "insects" are dead by the 40th chapter, a few of the recurring characters even say so after getting back up from the ground.
* InadvertentEntranceCue: One scene has Imomushi stating she didn't necessarily come to Alice's school to fight her but is interested on the reward on her head. Cue awkward silence as Alice enters the room.
* InsectQueen: Sara, who is Army Ant-themed, can dominate weak-willed people and is followed around by brainwashed minions. [[spoiler:Turns out she's tasked with guiding them, but isn't the one doing the brainwashing...]]
* InvoluntaryGroupSplit[=/=]LetsSplitUpGang: When a bunch of assassins invade Alice's school to kill her, all she wants is to get her friends out of there, but they keep getting separated for a reason or another.
* {{Irony}}: The two times Oki ordered an opponent to be her slave, she became enslaved instead.
* ItsPersonal: Hibiki hates Alice because she [[spoiler:killed Kumo. He doesn't realize Kumo forced her to do that.]]
* ItRunsOnNonsensoleum: Other than Kabutomushi and her implanted armor, most of the characters don't seem enhanced. But even when their tricks are just plain supernatural, they're able to do them because they somehow fit in their insect motif, without any further explanations other than [[HandWave "they did special training"]].
* JapaneseBeetleBrothers: Kabutomushi is a girly, intense and incredibly strong rhino beetle lady. No Stag Beetle-themed person has shown up in either story.
* JusticeWillPrevail: Having watched a little too much tokusatsu shows, Hibiki claims to fight for justice and love, and regards his opponents as evil.
* {{Kiai}}: Hibiki repeatedly shouts [[ThePowerOfLove "LOVE"]] [[http://mangafox.me/manga/arachnid/v05/c024/31.html while stomping people]] and Dinoponera [[EvilLaugh laughs madly]] when pummeling faces.
* KillingIntent: When in danger, Alice puts all her focus on how she can kill or at least terrify her enemies. Only Suzume Bachi [[KnowWhenToFoldEm gets her afraid enough to flee once.]]
* KnightTemplarParent: Alice's father is implied to be one.
* LanternJawOfJustice: "House Cricket" Hibiki and "Sand Cricket" Riokku.
* LateArrivalSpoiler: The cover for Volume 11 depicts Sasori with her surprise scorpion tail. Volume 12's cover heavily hints at a big plot twist, but at least it had already been revealed in the end of the previous volume.
* LimitedWardrobe: Alice pretty much stays in her school outfit.
* MadScientist: Jigabachi, who [[spoiler:installed the mechanic tail on Sasori]].
* MakeMeWannaShout: While bored from fighting Hibiki, Dinoponera suddenly stuns everyone in the corridor with a loud scream. [[spoiler:She does it again later to escape after being defeated by Alice, but Kabutomushi isn't affected and almost crushes her.]]
* MaleGaze: Lots of it.
* ManlyGay: Hibiki.
* MartialPacifist: Despite her killing instinct, Alice would rather not kill people and fights only to protect herself and the few friends she has.
* MercyKill: [[spoiler:Alice does this to Kumo.]]
** Caterpillar to one of Bullet Ant's victims.
* MissingMom: Alice's mother, who was DrivenToSuicide after too much stress. Dinoponera's mother died from gunshot wounds while protecting her. [[spoiler:And the assassins who served as father figures for them are both dead.]] Yoriko's mother died by childbirth and her father is always away. Oki was left abandoned in a trashed home as a baby before being taken to an orphanage.
* NearDeathExperience: This trope tends to trigger the killer in Alice, while Dinoponera is shown on a flashback awakening her own concentration technique to survive an ambush, at [[ChildSoldier a very young age]].
* NoSell: Dinoponera seems immune to blunt damage. She gets blown away by a kick to the face and then just stands up with [[SmugSmiler a smirk]]. After this she gets stomped countless times and just gets a bit embarrassed, without damage even to her clothes.
* NotWhatItLooksLike: After Oki defeats Geji, she undresses her to take her clothes, since Oki had [[ItMakesSenseInContext been dressed on a dominatrix getup by Digger Wasp.]] Alice, who didn't know anything, finds her doing this and gets disturbed. Because she's ''[[LesYay jealous]]''.
* OnceMoreWithClarity: Some scenes involving [[spoiler:Kuramoto]] are later retold from her perspective, showing what her true intentions were.
* OrphanageOfFear: The Orphanage Miki[=/=]Imomushi and Mika lived in. The employees beat Miki for making trouble at school and the director's daughter, who goes on to become the main villain, sexually abuses Mika for years in exchange for Miki not being sent to a reformatory.
* PeoplePuppets: Alice can trap people with her threads to force them to move against their will. And if she happens to be paralysed, she can pull herself around too. She calls it [[GratuitousItalian "Marionette del Ragno"]] in chapter 49.
* PosthumousCharacter: [[spoiler:Kumo's]] commmentary on some characters' abilities is remembered by those who knew him.
* {{Prequel}}: "Caterpillar" Imomushi's storyline.
* ProfessionalKiller: The insect-themed assassins.
* PsychoLesbian: Gokiburi sets a standard when she tries to make Alice her slave and orders her to crawl naked around the school. While she softens up from becoming good friends with Alice, villainesses Army Ant Queen and Ageha go further with the trope.
* RooftopConfrontation: Alice fights her master and father figure Kumo on the top of a building. [[spoiler:[[BookEnds At the end of the Arachnid Hunt]], she confronts her evil disappeared biological father, Suzume Bachi, on the rooftop of the Ouran High School]].
* SailorFuku: Dinoponera likely wears one to look like a [[Franchise/SailorMoon Sailor Scout]]. The other girls don't anymore.
* ScaryScorpions: Sasori revels in [[TheParalyzer paralyzing and torturing]] people to death with her poisons.
* ShadowArchetype: From her looks to personality, backstory and abilities, Dinoponera is pretty much Alice with a more physical fighting style and whose lonely background as a child mercenary made her [[{{Jerkass}} mean and deranged]].
* SkywardScream: Alice after [[spoiler:she kills Kumo]].
* SmugSmiler: A frequent expression on female antagonists such as Sasori, Geji and Dinoponera.
* SmugSuper: Every insect assassin is so incredibly smug about thier abilities that the otherwise humble Alice can't help but join in to counter their taunts.
* SpidersAreScary: Alice normally is [[BewareTheNiceOnes a gentle and kind girl]], but in battle she becomes much colder and creepier.
* StrongAnts: Some antagonists are ant-themed. "Army Ant" Sara is helpless in battle but [[TheMinionMaster turns the entire student body of her school into her brainwashed minions.]] Dinoponera comes equipped with stings and is shown to be greatly strong, fast and resistent. The prequel has Dinoponera's foster father, Paraponera (Bullet Ant), being a difficult opponent to Imomushi who survives a grenade exploding in his face.
* SuperDrowningSkills: Alice can't swim.
* TheSyndicate: "The Organization", which targets people they deem worthless to take over their commodities. They have much control over the world and are untraceable.
* ThatWasNotADream: After Alice beings Oki home, she dreams about the roach girl sweating oil to bypass the sound detection of her thread and then shooting Yoriko to death. [[CatapultNightmare Alice wakes up]] to see that Oki really escaped from her with that bizarre method... but only [[PantyThief to play with Alice's panties]].
* TheseHandsHaveKilled: Alice may be determined to kill when necessary but isn't proud of that.
* TooPowerfulToLive: The excuse [[spoiler:Kumo]] uses to fight Alice to the death.
* TheUglyGuysHotDaughter: Dinoponera to Bullet Ant, but she's adopted.
* UnPerson: The Organization owns all records of their members' existances and is able to erase those if they die. Alice refuses to join them to avoid becoming this.
* UseYourHead: Imomushi's main attack is to catapult herself head-first on enemies.
* WebcomicTime: About thirty chapters all happened in one afternoon. ''Still'' going.
* TheWorfEffect: Oki claims she's the fastest among the assassins, yet gets easily beaten when someone turns out to be more danguerous than her. Kabutomushi and Imomushi, as strong as they are, can't harm Dinoponera at all. Dinoponera goes on to casually slap around some other assassins only to also fall victim to this trope when she meets Sasori.
* {{Yandere}}: PlayedForLaughs when, after befriending Alice, Oki tells her she would kill any boys Alice liked.
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