History YMMV / Animorphs

** Much of the series can be described as [[WidgetSeries 90s weirdness]] - "Weird" ''was'' one of the rules of TheNineties.

** Thanks to their fantastic capacity for imitating their hosts, Yeerks can be anywhere, even inside the people you know intimately. Yes, you could be talking to an alien parasite who's putting on an elaborate act and doesn't mean a word he/she says while your genuine best friend/close sibling/beloved parent/ significant other is watching you be fooled, and is mentally sobbing because no one realizes they're a prisoner inside their own head, and you'd have no way of knowing. ''At all.'' The Yeerks make a few rare mistakes, due to having their own agendas and personalities, but aside from a couple isolated incidents the Yeerks are absolutely undectectable. Combined with the books' LiteraryAgentHypothesis setup, this makes for some very creepy MindScrew.

** [[spoiler:David]] murdering Jake and Rachel's cousin Saddler is played this way. Previously given some sympathy due to his having lost his parents and been forcibly recruited by the Animorphs into a war he doesn't want to fight, [[spoiler:David]]'s attempts to kill on Tobias and Jake were the start of a slide down the slope to straight up villainy. [[spoiler:David]]'s decision to unplug Saddler, stash the body, and replace him, is the point at which the characters and the narrative stop treating him with any sympathy, and the point at which the audience realizes that there is going to be no reconciliation.

* GrowingTheBeard: ''Literature/{{Animorphs}}'' at first did it with the third book in the series; while the first two had helped to establish the core plot and the setting, the third book took a more unique turn, centering around Tobias, the most mysterious member of the group who in the previous books had been [[ShapeshifterModeLock trapped in the form of a hawk]]. Book number 19, ''The Departure'', coupled with books 20-22 ("the David Trilogy") are also noted for elevating ''Animorphs'' beyond usual middle reader books. Other points later in the series' 54-book run could also be considered growing the beard, depending who you ask. Perhaps when [[spoiler: Marco's mother is revealed to be Visser One, when the conflict escalates to a full scale war in the later books, and more gradual as the characters grow more mature over time.]] There is also a very notable beard-growing for the companion books such as the Andalite Chronicles and Hork Bajir chronicles, with much more mature and engaging storylines following on characters on exotic alien worlds. On the other hand, some fans argue that the later books in the core series saw a decline in quality, where Applegate had many of the books ghostwritten (though she heavily edited them to fit), and in the climax of the series where some were upset at [[spoiler: Rachel and Ax's deaths]]. It's telling that the only book in the mid-to-late range that is generally well-received by fans is a take on ''Series/StarTrekTheOriginalSeries'''s "[[Recap/StarTrekS1E5TheEnemyWithin The Enemy Within]]" which is also the only book not ghostwritten until the final two.

* GrowingTheBeard: ''Literature/{{Animorphs}}'' at first did it with the third book in the series; while the first two had helped to establish the core plot and the setting, the third book took a more unique turn, centering around Tobias, the most mysterious member of the group who in the previous books had been [[ShapeshifterModeLock trapped in the form of a hawk]]. Other points later in the series' 54-book run could also be considered growing the beard, depending who you ask. Perhaps when [[spoiler: Marco's mother is revealed to be Visser One, when the conflict escalates to a full scale war in the later books, and more gradual as the characters grow more mature over time.]] There is also a very notable beard-growing for the companion books such as the Andalite Chronicles and Hork Bajir chronicles, with much more mature and engaging storylines following on characters on exotic alien worlds. On the other hand, some fans argue that the later books in the core series saw a decline in quality, where Applegate had many of the books ghostwritten (though she heavily edited them to fit), and in the climax of the series where some were upset at [[spoiler: Rachel and Ax's deaths]]. It's telling that the only book in the mid-to-late range that is generally well-received by fans is a take on "The Enemy Within" which is also the only book not ghostwritten until the final two.

* SpecialEffectFailure: The show is infamous for, among other things, particularly bad special effects. You can see the weave in Visser Three's tailscythe, and the Hork-Bajir model (they only had one) is memetically bad. The [[RayGun dracon beams]] were just flashlights.

* AudienceAlienatingEnding: While it's bad enough that the (still living) main characters are just as, if not more, broken and traumatized despite defeating the Yeerks, the knife twist comes when they decide to initiate what is most likely a suicide attack against [[DiabolusExNihilo an extremely powerful enemy that had only been vaguely alluded to in the previous books and just sort of shows up out of nowhere.]]

* DoNotDoThisCoolThing: An in-universe example: many of the first twenty books in the series open with the Animorphs engaging in comedic shenanigans using their powers while in the process breaking a wide range of laws from breaking-and-entering to theft to assault and possible ''[[FridgeHorror murder]]'' towards people [[KickTheSonOfABitch they judge as deserving it]]. Skip ahead to the David trilogy and the team contracts a shared case of MoralMyopia, with Jake threatening new Animorph David for the relatively tame sin of breaking into a hotel room.

* BrokenAesop: The book where they turn into cows. Sure, animals are treated horribly in meatpacking plants, but [[CarnivoreConfusion burgers are delicious]]! [[EnforcedTrope This one was reportedly deliberate]]: Applegate hated what the ghostwriter had done with the book and inserted a new ending to [[BrokenAesop blow the Aesop on purpose]].

* AcceptableHobbyTargets:
** ''The Resistance'' features a family of ''Franchise/StarTrek'' loving campers who are, to put it altogether too mildly, not portrayed in a very positive light. ''Franchise/StarTrek'' fans reading the series later were not amused, though many of the Animorphs -- [[OffendingTheCreatorsOwn and Applegate herself]] -- are avowed fans of the franchise.
** When the tiny Helmacron spaceship lands in a Goodwill store, Jake pretends to have accidentally donated his toy spaceship and asks the worker if he can get it back. The worker suspiciously asks him what ''kind'' of spaceship, and rattles off a list of alien spacecraft from ''Franchise/StarWars'', ''Franchise/StarTrek'', and ''Series/BabylonFive'', leading Jake to mutter about of all the workers in all the Goodwills, they got the one who happened to be a sci-fi geek. This is less a dig at ''being'' a sci-fi fan (Cassie and Rachel also speculate on it, and deliberately go to Jake ''because'' he would be able to choose the franchise that the Helmacron ship would most likely pass as a toy from), and more a dig at the ''inconvenience'' of their bad luck.
** When SixthRangerTraitor David is introduced, one of the early hints that he isn't to be trusted is the fact that he likes heavy metal bands like Megadeth and horror comics like Spawn, compared to the tamer works that the main characters prefer.
* AcceptablePoliticalTargets:
** Nazis are semi-regularly mentioned by the kids as a shorthand for evil. Though the summit meeting scene manages to slip in a comical shot at a [[NoCelebritiesWereHarmed certain world leader with a comical drinking problem]]. [[spoiler: Probably Boris Yeltsin, for those of you who aren't 90's literate.]]
** At one point in the epilogue, several RightWingMilitiaFanatic groups spring up in response to the discovery of aliens. Not much depth is given to them.

** Andalites are monsterfuckers.[[labelnote:Explanation]]The first two ''Chronicles'' books are both about an Andalite who falls in love with a member of another species, becomes a nothlit, and has a child with them. This led to a bunch of jokes about how Andalites only invented the morphing power so they could have sex with aliens.[[/labelnote]]

* OneSceneWonder: The ant that gained the power to morph from the blue book and has a run in with Cassie.

* RetroactiveRecognition: Shawn Ashmore (Jake) would go on to the ''Film/XMenFilmSeries'' and Paulo Costanzo (Ax) would later go onto ''Series/{{Joey}}'' and ''Series/RoyalPains''.

** The Auxiliary Animorphs, the handicapped kids who are also given the morphing power are mostly used as RedShirts in the last couple books despite some good potential.

** [[GreaterScopeVillain Crayak]] is an alien and member of The Highest Powers who acts as the series' GodOfEvil. A nearly omnipotent [[TheSocialDarwinist Social Darwinist]], Crayak seeks to create a universe ruled by one species and one species alone. To that end, Crayak engineered the Howlers, a race of psychopathic {{child soldier}}s who think that killing is a game, and used them to gruesomely exterminate countless species, including the pacifistic Pemalites and Graffen's Children. In order to ensure that the Howlers' HiveMind is never contaminated by memories of defeat, Crayak obliterates any Howlers who [[YouHaveFailedMe fail him]]; he also destroys any Howlers who realise that their victims are people too. Not content with having created one of the most feared races in the galaxy, Crayak also lends his godlike might to other vicious species, secretly backing the Yeerks and other would-be {{galactic conqueror}}s; he plans, for example, to have the Yeerks enslave humanity, [[YouHaveOutlivedYourUsefulness only to then be wiped out by the Howlers]]. In a series filled with shades of grey, Crayak was as close to pure, unadulterated evil as one was likely to get.

** [[BigBad Esplin 9466 (the greater)]], better known to the cast as Visser Three. The only Andalite-Controller in existence, Visser Three is the sole Yeerk with the power to [[ShapeShifter morph]]. In his first appearance in the series, he morphs into a horrific monster and eats Prince Elfangor alive, firmly establishing his characterisation for the rest of the series. A low-functioning sociopath with a HairTriggerTemper, Visser Three takes every opportunity he can to kill people, by personally decapitating his subordinates and their hosts left, right, and centre. He repeatedly eats those he dislikes, and outrages other Yeerks when he morphs a ''Yeerkbane'', one of their few natural predators, and uses it to devour subordinates who have [[YouHaveFailedMe failed him]]. As the commander of the invasion of Earth, Visser Three cares nothing for casualties and is willing to [[WeHaveReserves write off thousands of his own Yeerks]] rather than negotiate. He is the [[BadBoss worst boss]] in the series, and no matter how awful things got, always gave the Animorphs the most nightmares.

** The Hork-Bajir are a race of dumb, friendly bark eaters who were nearly wiped out in an attempt to deprive the Yeerks of hosts. The kicker is that it didn't even ''work''. Those few Hork Bajir who weren't killed were successfully infested with Yeerks.

*** Marco to a lesser extent, for [[KillEmAll a certain thing]] that happened in the season 1 finale.

* PairTheSpares: Possibly. One episode of the TV adaptation ends with [[spoiler: all six protagonists slow-dancing to a romantic song: Cassie and Jake, Rachel and Tobias, and Marco and Ax.]] In the US, this was the last episode aired, and it's pretty easy to interpret it as a LastMinuteHookup.

* MagnificentBastard: [[AllPowerfulBystander The Ellimist]] was once a mortal Keetran known to his friends as Toomin, who, through a series of cosmically unlikely events, ended up becoming a reality-warping being. As the SoleSurvivor of his kind, Toomin's transformation into the Ellimist begins after breaking free of "[[TheAssimilator Father]]". Toomin learns to steal the millions of assimilated minds from Father, then uses this near-limitless knowledge to integrate himself into a super advanced spacecraft, travelling the galaxy as a technological deity to help planets prosper. However, the Ellimist comes into conflict with [[OmnicidalManiac Crayak]], who seeks to eradicate all life. Unable to stop Crayak's trail of death, the Ellimist instead counters by spreading new life on uninhabited planets that outpaces Crayak's work. The two technological gods battle one another, wiping out a tenth of the galaxy in the crossfire, which ends in the Ellimist and later Crayak entering a black hole and merging with space-time to become true gods. Continuing to play a CosmicChessGame, Crayak is responsible for the Yeerk crisis ravaging the galaxy, while the Ellimist manipulates the formation of the [[Characters/AnimorphsAnimorphs Animorphs]] as his warriors. The Ellimist assists the Animorphs from the sidelines numerous times, often exploiting loopholes to give them help without technically breaking the rules of the game.

* AuthorsSavingThrow: Tobias and Rachel have much more chemistry than in the novels.

* AuthorsSavingThrow:
** When the preview pages for ''The Invasion'' came out, a lot of fans thought that [[LatinoIsBrown Marco's skin tone was too light]]. He's darker in the actual books.
** The adaptation of ''The Visitor'' re-writes some aspects of the scene where Rachel is harassed by an older man who she scares off with her elephant morph, removing some of the UsefulNotes/VictimBlaming that the Animorphs did to her as well as turning the older man into a younger teen that Rachel was more confident she could handle on her own.
** In the original ''The Invasion'' Visser Three acts like he's meeting Elfangor for the first time, even though ''The Andalite Chronicles'' would establish that they have an extensive history together, including [[spoiler: Elfangor being partially responsible for Visser Three getting an Andalite body in the first place.]] The graphic novel adaptation fixes this by having him instead comment that Elfangor has become "quite a legend" since they last met.

* PairTheSpares: Possibly. One episode of the tv adaptation ends with [[spoiler: all six protagonists slow-dancing to a romantic song: Cassie and Jake, Rachel and Tobias, and Marco and Ax. In the US, this was the last episode aired, and it's pretty easy to interpret it as a LastMinuteHookup.]]

* ViewerPronounciationConfusion: Some people pronounce Yeerk as "yerk", while others pronounce it as "year-k". The TV show went with the former, while the audiobooks went with the latter.