History Animorphs / TropesIToP

** Averted in the Andalite Chronicles. While on an andalite ship that has lost atmosphere, Lauren and Chapman are given andalite emergency oxygen devices. The gas mixture in the device is formulated for andalite physiology and it is made clear Lauren and Chapman are being poisoned by them. The only reason they aren't removed is the vacuum would kill them quicker.

* NoCelebritiesWereHarmed: Jeremy Jason [=McCole=] (from #12) of the fictional TV series ''Power House'' is totally not an expy of ''HomeImprovement''[='s=] Jonathan Taylor Thomas.

* MillionToOneChance: At some point the reader may sit back and think, "Hey, wait a second. Yeerks are a race with insanely superior weapons. Not only that, but anyone can be a Controller. And this is a worldwide invasion. The heroes are six teenagers who live in a small town in California that can turn into animals? How can they stop the invasion? A bunch of animals couldn't beat the U.S. Army, never mind the Yeerks." This is lampshaded many, many times throughout the series, as the kids admit that at best all they do is slow down the Yeerks from time to time. They mostly lose battles and they agree that they'll never really be able to beat the Yeerks. They ''do'' eventually win, due in large part to the morphing technology being so dangerous and versatile. Rachel sums it up pretty well [[spoiler:during David's betrayal]] when the kids are reflecting on how hard it is to kill an Animorph:

* LastNameBasis: Chapman. In the main series, he's the main characters' assistant principal, so it's rather understandable that they refer to him by his last name, with or without a "Mr." in front. In ''The Andalite Chronicles'', he reveals that his first name is "[[FailOSuckyname Hedrick]]", but he prefers to be called "Chapman", anyway.

* IAlwaysWantedToSayThat: Rachel and "ItWasADarkAndStormyNight."
** Marco and "Let's do it," Rachel's catchphrase. He just wanted to say it ''first.''

** In an interview, Creator/KAApplegate stated that Rachel's "Dark and stormy night" and "I always wanted to write that" lines were Applegate speaking to the readers.
* IAteWhat: Inverted. Ax eats all kinds of stuff (cigarette butts, engine oil and a paper plate to name a few) but it doesn't really bother him. He can't see what the others are getting so upset about.
--> '''Cassie:''' Were the nachos good?
--> '''Ax:''' They tasted of grease and salt. Plus, there was another flavor that reminds me of some delicious engine oil I tried once. Oil. Oil-luh.
--> '''Jake:''' Ax...You know how I mentioned you can't eat cigarette butts or dryer lint? Add engine oil to the list.

* IdiosyncraticEpisodeNaming: The regular series books are all in the form of "The <Noun>." Likewise, the three prequel books are all in form of "The <Species of the Person the Book Focuses On> Chronicles."

* IfYouKillHimYouWillBeJustLikeHim: [[spoiler:When the war ends, Jake refuses to kill Visser One (previously Three). Tobias, enraged, demands to know why, claiming that Visser One was the one responsible for the entire war. Jake replies quietly that they "don't kill prisoners."]]
** [[spoiler:The Visser immediately mocks his hypocrisy; Jake has just killed seventeen thousand unarmed, helpless Yeerks. Not to mention he and the others had blown up the shopping mall to take out the Yeerk pool beneath it, which killed thousands of unhosted Yeerks and hundreds of innocent people.]]

** ImmortalityInducer: During their adventure back in time (MM3), Jake (and the others, after his death).
* ImpactSilhouette: In book #25, ''The Extreme'', the Animorphs (as Polar Bears) are being chased by Venber at the Arctic Yeerk base. Marco stops quickly and a Venber misses him, slamming through a steel door and making a vague Venber-shaped hole in it. Marco even calls it a "Bugs-Bunny-runs-through-the-door kind of hole."
* ImperialStormtrooperMarksmanshipAcademy: Visser Three: "Would it be asking too much for one of you to actually ''hit'' something?!!"
* ImportedAlienPhlebotinum: The Escafil Device, which transfers the morphing power.

* InsaneAdmiral: Yeerk Vissers in general. Visser Two from ''The Deception'' is utterly ''bat-shit crazy'', and gets bonus points for taking over an actual admiral.

* TheInternetIsForPorn: Actual pornography is implied once or twice, but this being a kids' book, we get a more toned-down version: Marco uses the internet almost exclusively to look up scantily clad girls.
* InterspeciesRomance: Aldrea and Dak Hamee, Elfangor and Loren. Also, Tobias and Rachel, sort of (Tobias is stuck as a hawk, but he was originally a human and thus identifies as one. [[spoiler:Also, while his original form is ''genetically'' fully human, his father was actually an Andalite in human morph, so it might be vaguely interspecies even if he wasn't a hawk most of the time.]])
* ImNotDoingThatAgain: Frequently used as a catchphrase, but once very serious, when the kids morph ants - the ant morph has some ''very'' disturbing side effects.

--->< I will gladly fight this Controller, and even, in fair battle, kill him, but I am not a torturer. >

** Andalites are the "good guys" and Ax often points out the immorality of human actions for Aesop effect - for instance, he states that human wars are often pointless and needlessly cruel. However, setting aside the horrifying ruthlessness of the Andalite military, Andalite citizens themselves are no saints. They have a variety of distasteful flaws, such as extreme arrogance. Most notably, they intensely hate ''vecols'' - the disabled, who, they believe, should ostracize themselves from society to preserve themselves from the shame of being "incomplete" and therefore worthless. Most notably seen when Ax strongly objected to meeting Mertil, the marooned Andalite fighter pilot from #40, The Other, and Mertil's companion Gafinilan opposed the other Animorphs meeting him as well, on the grounds that subjecting Mertil to the public eye would be shameful.
** Hork-Bajir ''used'' to be a species of InnocentAliens. It wasn't that they were pacifist - they simply didn't understand the concept of fighting. The Yeerk-Hork-Bajir war, however, changed that. Hork-Bajir are still simple pacifists in nature, but they're far from the InnocentAliens they used to be.
** Also, [[spoiler:the Howlers, who are, from a certain standpoint, the most innocent species that the kids meet. Unfortunately, for Howlers, "fun" means "killing the shit out of everything they see." Howlers are a species of genetically engineered killing machines. It's just that they don't know that killing is wrong, and Crayak preserves their naivete by altering their collective memory]].

* JustForTheHeliOfIt: Tobias and Rachel (in bird morph) are following a woman by latching on to a taxi. Then Tobias, for some reason, gets it into his head that they'll lose her if they stay on the taxi, so he flies up to a nearby helicopter and grabs on to the skids, a dangerous act and, as it turns ot, pointless, since the helicopter ends up landing at the airport where the woman ([[spoiler:Visser Three in morph]]) was going.
* KangarooCourt: Visser One is tried as a traitor and an Andalite sympathizer, but in actuality, Visser Three set up the whole thing and convinced the Council to go through with it in order to usurp her position. Additionally, all Yeerks in command of the invasion received these after the war. Unusual in that they actually were guilty of war crimes, but it's noted that no human would have voted against conviction regardless. And in any case, the protagonists had their own war crimes under their belt and were not even prosecuted: Viser 1's lawyer brings up Jake's killing thousands of noncombatant yeerks as an example.
* KickedUpstairs: Tom's second Yeerk, who is improbably promoted to chief of security despite being the ''last'' Yeerk qualified for the position. It's implied that he's promoted simply because the job requires working closely with Visser Three, which GenreSavvy Yeerks recognize immediately as a death sentence.

* KidHeroAllGrownUp: At the end of the final book. It's not very pretty. [[spoiler:Jake is a ShellShockedVeteran, Rachel died just before the war's end, Tobias retreats to the woods to mourn her, Ax becomes a prince but is captured and infested by a mysterious new being, and Marco becomes a materialistic celebrity. Cassie becomes an ambassador, and is possibly the only one to survive the BolivianArmyEnding later.]]
** A previous book has an alternate universe where the Yeerk invasion succeeded. [[spoiler:Jake became an infested drone, Cassie was also infested but with a Yeerk fighting the empire, Rachel was crippled too badly for morphing to heal her, Marco is controlled by the dictator of Earth Visser Two, Ax is dead, and Tobias has trapped himself in morph as Ax pretending to be Elfangor back from the dead.]]

* KillThePoor: One of the Megamorphs books begins in an alternate universe where the homeless "are rounded up and shot."
* KindRestraints: The team has to tie up Jake when he's accidentally infested, to starve out the Yeerk in his head, and they have to constantly watch him on top of it, because they know the Yeerk will try to morph to free him from the restraints.

** Ax's favorite TV show is "These Messages", aka commercials.
** Ax and TV in general. But partially subverted in that Ax hates all human music.

* KnowWhenToFoldEm: [[spoiler:At the end of the final battle. After it becomes clear that Tom plans to kill Visser One using his own personal Blade ship, the visser essentially surrenders to the kids once they arrive on the bridge.]]
** [[spoiler:Similarly, once the Controllers onboard the Pool ship realize what has happened, they surrender to the kids in exchange for amnesty and a chance to acquire the morphing power (to permanently morph animals and move away from parasitism). The surrendered Yeerks got off quite well, all things considered.]]
** In ''The Capture'' this is revealed to be a major tenet of Yeerk psychology: Yeerks will give up when the odds don't favor them rather that fight against impossible odds as humans do. This semi-defeatist mindset is presented to explain away the BondVillainStupidity of Jake's Yeerk, but later books are consistent with this, as it comes up again in VISSER and ''The Answer''.

** Averted with [[spoiler:Tobias's mother, Loren.]]
* LastNameBasis: Chapman. In the main series, he's the main characters' assistant principal, so it's rather understandable that they refer to him by his last name, with or without a Mr. In ''The Andalite Chronicles'', however, he reveals that his first name is Hedrick, but he prefers to be called Chapman, anyway.

** The reader never finds out who burned down Joe Bob Fenestre's house, after Jake told him that inside that house was the only place he'd be safe from them. Jake says that the list of potential suspects includes Visser Three, Cassie, and himself.

** In #41, the whole BadFuture thing turns out to be a mind exercise brought on by some other entity that is studying humans. It's not Ellimist or Crayak... So who was it?
** The ending of the whole series, actually…more or less. [[spoiler: We don't know what the hell The One is, what happened to Ax, or even whether or not Jake, Marco, Tobias, and Ax survived the BolivianArmyEnding.]]

* LikeParentLikeSpouse: Tobias's mother Loren is a feisty, fearless, often reckless and smartmouthed blonde who falls for a guy outside her species.... hmm, I wonder who that sounds like.

** Ax, and Andalites as whole, do not have mouths and if they morph into a creature with one then the feeling of taste drives them mad. Every time Ax turns human his friends have to stop him from devouring everything from cinnamons buns to cigarette butts.
** Yeerks naturally are blind slugs, and possession of their victims is intoxicating because of all the new senses they gain. Even Visser Three, the Yeerk DragonInChief, fell in love with the sense of sight.
* LineInTheSand: Literally. After the Yeerks find out where the Hork-Bajir valley is located, they plan to storm it and kill everyone. Jake and his friends attempt to explain to Toby that going into battle is suicidal, and to demonstrate his point Jake draws a line in the sand and asks the Hork-Bajir to vote on which course of action is the smartest. Jake's point backfires when every Hork-Bajir votes to fight back.

* LiteraryAgentHypothesis: Mentioned at the start of every book, but it gets weird because [[spoiler:Rachel continues to narrate immediately after her death.]]
* LivingWithTheVillain: Jake's brother was a Controller.
* LoadsAndLoadsOfCharacters: Let's see: Jake, Marco, Cassie, Rachel, Ax, Tobias, David, Tom, Eva, Peter, Loren, Naomi, Jordan, Sara, Chapman, Erek, Visser Three, Visser One, Toby, Jara Hamee, Mr. King... And none of those are one-shot characters, either.

* LosingAShoeInTheStruggle: Morphing often results in lost, if not outright ''destroyed'', footwear.

* LukeIAmYourFather: Twice. [[spoiler: Marco's mother]] has been taken over by the leader of the invaders. [[spoiler: Tobias' father]] was the war hero alien who gave them their powers. Justified late in the series; the Drode whines that [[spoiler:the Ellimist stacked the deck to get Marco and Tobias, along with Ax and Cassie, into the Animorphs]].

* MacGuffin: Several over the course of the series, including the Pemalite crystal, the blue box, the Anti-Morphing Ray, and the Pemalite ship -- but the ultimate MacGuffin is the Time Matrix, which was the catalyst to the Andalites and Yeerks even ''discovering'' Earth, let alone the war itself.

* MadeOfIron: Because the kids can morph or demorph to heal all bodily injuries, it takes a lot to kill them. Typical battles include at least minor injuries. More commonly the kids suffer major injuries; arms being cut off, major blood loss, et cetera. The most memorable example was in the second last book, when Jake, woozy from blood loss, gets shot in the head by a human-Controller. Miraculously he survives long enough to demorph.
** Bear-Rachel getting an arm cut off and using it as a weapon also qualifies as memorable.
** Also, after reassuming the original form, the morpher's bodily injuries could theoretically be healed. In Megamorphs 2, Tobias says that he should be able to heal his broken wing after morphing and demorphing. Ergo, any bodily injury sustained in the original form of the morpher should be repaired, including brain damage, amputation and the like. Age would remain unaffected as DNA degrades with age: a newborn cloned from a 27-year-old's cells will essentially start with 27-year-old DNA and cells.
*** James, the leader of the Auxiliary Animorphs, is crippled due to an accident rather than a genetic disease, so after demorphing from pidgeon he finds that he can walk again. Similarly, Loren's blindness is cured by morphing. Marco also heals a dog bite by morphing then demorphing.

* MagicPants: [[AvertedTrope Averted.]] Morphing is not kind to most clothing. The only exceptions are skin-tight clothes like leotards or wetsuits, and shoes always come out looking like, as one character described it, "a pack of dogs played tug of war with them."

** A complete list of Jake's nicknames: Big Jake, Fearless Leader, Jake the Mighty, Jake the Yeerk-Killer (sometimes Big Jake the Yeerk-Killer, used mockingly), Jake the Ellimist's Tool, and (in the alternate timeline from Megamorphs #3) Supreme Leader. Ax calls him "Prince Jake" but this is an Andalite military designation.
** And, of course, Marco's always calling Rachel "[[XenaWarriorPrincess Xena: Warrior Princess]]".

** After the war, it's Aximili "of Earth".

* MamaBear: Both Loren and Eva qualify, but Naomi, for all her bossiness, thickheadedness and inflexibility, is the epitome of Mama Bear. In one instance, she attacks a grizzly bear that she thinks poses a threat to her daughters Jordan and Sara with a ''spice rack'', and knowing her, probably would've won if it weren't for the fact that the bear was her eldest child.
* ManipulativeBastard: Cassie, Marco, David, The Drode. But most of all, Jake, who becomes more and more manipulative as the series progresses.

* MauveShirt: Most of the named "auxiliary Animorphs".

* MeaningfulName: Sometimes obvious, sometimes not. According to WordOfGod, LordOfTheRings references are everywhere; Yeerk is a reference to "Yrch", the Elvish word for Orc, and Elfangor's and Aximili's names are references to elvish cities.
** According to WordOfGod, Cassie and Marco are based off of Creator/KAApplegate and her husband, Creator/MichaelGrant, respectively. Applegate's first name is Katherine, so she's probably called Kathy a lot, which explains Cassie, and Marco sounds pretty similar to Michael.

* MilitariesAreUseless: the military doesn't seem very worried about the Earth being invaded by aliens (see ExtraStrengthMasquerade). [[spoiler:When they finally admit that aliens are indeed invading, they send some Redshirts to die to support the main cast, and give them heavy weaponry to toy with, but don't have a very important role in the end]].

* MillionToOneChance: At some point the reader may sit back and think, "Hey, wait a second. Yeerks are a race with insanely superior weapons. Not only that, but anyone can be a Controller. And this is a worldwide invasion. The heroes are six teenagers who live in a small town in California that can turn into animals? How can they stop the invasion? A bunch of animals couldn't beat the U.S. Army, never mind the Yeerks." This is lampshaded many, many times throughout the series, as the kids admit that at best all they do is slow down the Yeerks from time to time. They mostly lose battles and they agree that they'll never really be able to beat the Yeerks. They ''do'' eventually win, due in large part to the morphing technology being so dangerous and versatile. Rachel sums it up pretty well [[spoiler: during David's betrayal]] when the kids are reflecting on how hard it is to kill an Animorph:
-->'''Rachel''': Just us. Just us against an enemy that could become any living thing. An enemy that could be anywhere, at any time. An owl in a tree, a spider in your house, a cat in the night, and then... Then, when you were unprepared, when you were vulnerable, a lion or a tiger or a bear. I was starting to see why Visser Three hated us so much.
* TheMindIsAPlaythingOfTheBody: Morphs come complete with the animal's instincts and desires. Some are useful, some can be ignored, some (ant, Taxxon) are horrifying.
* TheMinnesotaFats: Elfangor, but only from Ax's perspective. In fact, the main reason the Animorphs go to rescue Ax is because they feel an obligation to any Andalite because of Elfangor's kindness. From his own perspective, Elfangor is more of a NiceJobBreakingItHero.

* MookPromotion: [[spoiler:Tom, who becomes an important antagonist late in the series, and a major player in the final battle.]]
* MoreThanMindControl: There are voluntary Controllers, people who willingly let a Yeerk infest them. Many of them are simply so alone, so desperate to be part of ''something'', that they're willing to give up their free will. The Sharing's main purpose is to find these sort of people and indoctrinate them.

* MundaneUtility: Includes getting keys off the pool floor and getting into concerts for free. Jake ''tries'' to forbid this, but he keeps failing miserably... especially when he wanted to go to both concerts.

* MyGodWhatHaveIDone: After the war, Jake is so guilty about [[spoiler:ordering to have the Yeerk pool flushed into space]] and [[spoiler:sending Rachel, his cousin, to kill Tom, his brother (the former dies in the process)]] that he is driven to clinical depression. As Marco puts it: [[spoiler: "He wore Rachel and Tom and those seventeen thousand Yeerks around his neck like the [[Literature/TheRimeOfTheAncientMariner Ancient Mariner and his albatross]] ... He could've snapped his fingers and had anything he wanted, but he didn't ''want'' anything. Except for Rachel and Tom to be alive. For Tobias to come back. To unlive that fateful order that doomed seventeen thousand Yeerks."]]
** The whole series exemplifies this, to some extent. The kids agree that self-defense is justified, but the problem is when you kill a Controller, you don't just kill the Yeerk; you're also killing the host, who is completely aware but unable to stop the Yeerk. The kids debate during the entire series what is acceptable when it comes to self-preservation and exactly how far is too far. Initially the kids take a very narrowminded, black-and-white view - "We have the right to do anything we have to to win" - but as they mature and experience more in the war their moral lines become blurred to the point that they don't know the difference between right and wrong.

* MythologyGag: [[spoiler: Jake's decision to [[RammingAlwaysWorks "ram the Blade Ship"]] in the series' ending mirrors Elfangor's decision to ram an enemy ship in ''The Andalite Chronicles''. While Elfangor won his battle involving that tactic, the result of Jake's decision is [[BolivianArmyEnding unclear]].]]

** “The Abomination” is a name given to Esplin 9466 after he infests the Andalite Alloran. Granted, he fights with a sledgehammer, but do you really want to piss off someone with a sledgehammer of monstrous morphs from dozen of systems?
** And from the Yeerks’ perspective, Jake is "Jake the Yeerk-Killer", and he earns the title.
** Ax is kind of amused when he learns that Yeerks refer to his brother as "Beast Elfangor."

* NarrativeProfanityFilter: Being teenagers, and this being a very realistic series, the kids swear and flip each other off a lot. Depending on the "explicitness" of the word, it may or may not be directly written. "Crap", "damn" and "hell" are okay. Nothing else is explicitly mentioned, though the reader can guess the exact word most of the time.

* NeverFoundTheBody [[spoiler:Visser One, who more or less makes a career out of this.]]
* NeverSayDie: Completely averted, and kinda [[LampshadeHanging lampshaded]] when Rachel initially thinks "I'm going to destroy [[spoiler:David]]," but then she corrects herself: she's going to ''kill'' him. "Destroy" is a "weasel word" because it's vague and almost meaningless (the exact reason it's considered more family-friendly and often used in kids' fiction), whereas kill means ''kill''.
** When a bunch of Star Trek fans insist to help kids protect the Hork-Bajir's valley from a Yeerk onslaught all is splendid until Jake starts giving some last-minute orders, including "to move the wounded to safety but leave the killed lie." The father of the Trekkies family then asks timidly if by "killed" Jake meant "stunned or captured" and Jake replies that no, by "killed" he meant "killed to DEATH".

* NoOSHACompliance: Repeatedly lampshaded in ''The Attack'' - the Iskoort homeworld is covered in super-structures comparable to God-sized Lego towers...with no safety railings whatsoever, to the heroes' confusion.

* NoCelebritiesWereHarmed: Jeremy Jason [=McCole=] (from #12) of the fictional TV series ‘’Power House’’, is totally not an expy of ''HomeImprovement''[='s=] Jonathan Taylor Thomas.
** And yet, real celebrities' names were dropped all the time. Noah Wyle of {{ER}} was mentioned a lot, and book 17 gives us no less than seven real celebrity names at the Planet Hollywood concert. Cassie and Jake even use David Letterman as a code word when talking about [[SixthRangerTraitor David]] in an insecure phone conversation.

** In #23, Tobias' last name is transcribed as "______" in dialogue. One fan theory is that his last name is Fangor, since Elfangor was his father and used the human name "Alan Fangor." Another fan theory is that, because The Ellimist erased all trace of Elfangor from Tobias' mother's memory and she married someone else, even though Tobias [[AWizardDidIt still existed somehow]], Tobias was given that man's last name. Whoever he was.

* NoOneGetsLeftBehind: Particularly memorably in #41 The Familiar.
* NoPaperFuture: Used to comedic effect and to demonstrate Applegate's mild dislike of computers: Ax can't believe that books were invented before computers, because he finds them much quicker and easier to use. (He's also surprised that the telephone was invented before the chat room.)

* NoSidepathsNoExplorationNoFreedom: Alternamorphs #1 is a rare literary example. Despite ostensibly being a ChooseYourOwnAdventure type gamebook, the author doesn't seem to understand the concept, because the story is completely linear and every "wrong" choice results in instant death. Oddly enough, the second book went to the opposite extreme to the point of unintentional deconstruction.
* NostalgiaFilter: An in-universe example: at the end of the series, Marco sees the years he spent fighting Yeerks as the "good old days". He remembers life-and-death battles as "cool, rock 'em sock 'em battles". He doesn't really seem to remember how much they scared the crap out of him at the time. But then, it's said that Marco has a much easier time adjusting to civilian life than the others, because he doesn't feel guilty about the things he's done.
* NothingIsTheSameAnymore: After Visser Three's [[spoiler:promotion to Visser One]], the war quickly escalates and missions become increasingly important. This culminates in the discovery of the "Andalite bandits'" true identities. The seriousness of the kids' new situation is highlighted by the revelation of Jake's last name.
* NotQuiteDead: After David leaves the barn, Jake sends Tobias to follow him. When Jake catches up, [[spoiler:David says that he's killed Tobias, and Jake sees Tobias' mangled corpse. But as it turns out, that wasn't ''really'' Tobias, just an innocent red-tailed hawk that happened by. David had simply lost Tobias early in the evening, and the latter had spend a good couple hours trying to find him.]]
** While the Helmacrons and the kids are inside Marco's body, he morphs into a cockroach. The Helmacrons shoot Marco's heart, rendering him ostensibly dead. [[spoiler:But, as Cassie suddenly recalls, stopping a cockroach's heart doesn't kill it - they have a backup system.]]

--->'''''Visser One''': So. Still not dead.\\
'''Jake''': No, visser, not quite dead.''

** Cassie gets an entire book dedicated to this in #19: The Departure
** Crayak also does this with Rachel.
** Also done with [[spoiler:the Howlers]] and the Pemalites, two alien species created by Crayak and the Ellimist. The [[spoiler:Howlers]] look like AlwaysChaoticEvil who kill everything in their path and the Pemalites are insanely pacifistic, but the two races, thanks to how they were designed, [[spoiler:actually had the exact same priority in life: to have fun. Their creators just gave them different ideas of 'fun']].
* NotSoExtinct: The Venber in "The Extreme". Though they're actually hybrids of Venber and humans brought back by the Yeerks.

* ObliviouslyEvil: The reveal regarding [[spoiler: the Howlers.]]

* OhCrap: A couple times, but most notably in the second-last and last books. First, when [[spoiler:Visser One realizes that the Animorphs have gotten onboard the ship]], and second, when [[spoiler:Tom discovers he's been had and the kids are still alive.]]
* OnceAcceptableTargets: The Yeerks are an in-universe example. In early books the kids (especially Ax) can't overemphasize how evil they are, talking about how they'll [[ForTheEvulz destroy the environment because they can]] and [[AcceptablePoliticalTargets comparing them to Nazis]]. But as the war goes on they grow to realize that not all Yeerks are cackling villains like Visser Three and even gain allies from the other side in the form of the Yeerk Peace Movement.
* OneWingedAngel: Technically all of the "battle forms" count, though Visser Three gets to do a classic example at least once every few books.
* OnlineAlias: Mostly features the "modern" kind: [=YeerKiller9=], Gump8293, Bball24, etc. But it also has some more hacker-like ones, like "Govikes" and "[=YrkH8er=]". The Ketrans use gaming names as well. [[spoiler: Like "Ellimist".]]
* OpenSaysMe: In ''The Warning'' Jake morphs a rhinoceros to invade Joe Bob Fenestre's home. The other Animorphs have to guide him due to the rhino's poor eyesight, and frequently have him 'open doors' where none existed before.
* OptOut: Right before the final battle, a lot of the Auxiliary Animorphs decide that they want to sit it out, due to the fact that their friend Ray was recently killed. Jake doesn't really care and makes them go anyway. ("We didn't give them morphing power so they could have fun flying around. This is when we need them. All of them. You're their leader, James, so lead.") [[spoiler: They then all get killed, which Jake expected to happen.]]

* OrdinaryHighSchoolStudent: All of them ([[TokenNonhuman excluding Ax of course]]). And Tobias, after the first book.

* OverlyLongName: [[spoiler:The Ellimist's real name is Azure Level, Seven Spar, Extension Two, Down-Messenger Forty-One. Ketrans' names are basically their address, which is why they tend to call each other by their chosen names or gaming handles, and his was Ellimist.]]

* PainfulTransformation: Actually, it's specifically mentioned that while there's no actual pain, it definitely feels like there ''should'' be.
* PantheraAwesome: Big cats make good battle morphs. Jake's main morph is a tiger, while David and James both had lion morphs. There were also times when the whole group morphed jaguars and cheetahs. Hell, even Tom's favourite battle morph is the jaguar.
* ParentWithNewParamour: Marco's dad eventually marries Nora Robbinette, his son's ''math teacher.'' [[spoiler:It doesn't last. Eventually, he's reunited with his NotQuiteDead first wife, and Nora becomes a Controller. Marco, either because it'll be easier on his father or because he wants to see his parents together again, lets him think that Nora was always a Controller. God only knows what happened to the dog...]]
* ParentalAbandonment: Tobias' dad is dead ([[spoiler:his dad is Elfangor, by the way]]), his mother is [[spoiler:blind and an amnesiac, and therefore unable to take care of him.]] Tobias is "raised" by his aunt and uncle, neither of whom want anything to do with him.
* ThePasswordIsAlwaysSwordfish: The access code for the Pemalite spaceship is '6'. That's it. Just '6'. It's justified, in that the Pemalites were incredibly peaceful and trusting. [[RealityEnsues They are also all dead; and the Yeerks cracked the code in about a second]].

* PayEvilUntoEvil: [[spoiler: Jake, before flushing the Pool into space, decides that Yeerks are subhuman parasites who deserve nothing but cold, frozen death: "They could've stayed home, I thought. No one had asked them to come to Earth. No more than they deserved. Aliens. Parasites. Subhuman."]]

* PhlebotinumBreakdown: Happened a couple of times with BodyHorror-riffic results. Rachel suffered a case of InvoluntaryShapeshifting, turning into crocodiles, ants, and elephants at inconvenient times. Marco got it even worse, turning into a series of TwoBeingsOneBody creatures. (Dude. Osprey-Lobster. Trout-Gorilla. Neither of which could breathe. And, of course, the mighty poo-bear! [Poodle-Polar Bear.])

* PowerAtAPrice: To quote Jake: "''The power made us responsible, see. Without the power the knowledge would have just been a worm of fear eating up our insides. Bad enough. But it was the power that turned fear into obligation, that laid the weight on our unready shoulders ... Power enough to win? No. Power enough to fight? Ah, yes. Just enough, little Jake, here is just enough power to imprison you in a cage of duty, to make you fight...''"
* PowerNullifier: The anti-morphing ray. Though we never actually find out if it works —- the Animorphs just manage to convince the Yeerks that it doesn't.

** Visser Three's Blue Band Guard. Named after the blue armbands they wear.

* PrettyBoy: Ax, in his androgynous male human morph, which is made of DNA from Rachel, Cassie, Jake, and Marco.

-->'''Marco''': I'm paranoid, sure. But that doesn't mean I don't have enemies.

* InformedJudaism: Jake and Rachel are presumed Jewish (most of their parents and siblings have Hebrew names, and Rachel flat-out states "My dad's Jewish," when they visit D-Day. Dialogue from #21 and #31 allow us to conclude that their dads are brothers.), but nothing of their beliefs or holidays is mentioned beyond that.

* KangarooCourt: Visser One is tried as a traitor and an Andalite sympathizer, but in actuality, Visser Three set up the whole thing and convinced the Council to go through with it in order to usurp her position.

* LightFeminineAndDarkFeminine: Cassie and Rachel respectively have shades of this.
** Funnily, not to be confused with their inverted skin tones.
** Also, possibly Rachel in ''The Separation'', when she literally splits into two different people after her starfish morph goes wrong. One is timid, caring, gentle, and pacifistic; the other is dark, ruthless, and obsessive.

'''Tropes from ''Literature/{{Animorphs}}''.'''

* MagicPants: Lampshaded very early on.

* ObliviouslyEvil: The reveal regarding the Howlers; they're a race of mass-produced child soldiers with no idea that what they're doing is wrong. The Animorphs manage to slip a peaceful memory into their HiveMind.