* AlternativeCharacterInterpretation: Thrax's unnerved reaction to Frank's subconscious makes you wonder if some of those memories Thrax saw were of a DarkAndTroubledPast that Frank took on his unhealthy habits to cope with.
* AnimationAgeGhetto: What inspired the film's overhaul from a gritty, profane PG-13 action comedy to a juvenile gross-out family flick and, ultimately, proved its failure.
* AudienceAlienatingPremise: For once, it was this and not a lack of advertisement on [[Creator/WarnerBros WB]]'s part that caused the film to flop. The film couldn't blend the live-action gross-out comedy with the animated buddy cop movie as each portion only detracted from the other, confusing audiences who were put off by the jarring juxtaposition of the two ideas in trailers.
* SugarWiki/AwesomeMusic: From the tail end of the credits, the Diane Warren love ballad "Why Did You Have To Be" by Debelah Morgan.
* CatharsisFactor:
** Whether you feel bad for her or not, it is truly satisfying to see Shane get off her school bus to follow the ambulance carrying her dad and disobeying her insufferable and unforgiving teacher Miss Boyd, who has spent the whole movie being a total bitch to Frank.
** Thrax falling into the container of rubbing alcohol and being utterly obliterated is an extremely crowd-pleasing moment.
** As he's the reason behind Frank's unhealthy habit, nearly caused his death, and being an utter {{Jerkass}} to Ozzy and Drix, it's incredibly delightful to watch Mayor Phlegmming be called out by Leah for caring more about being re-elected than about the lives of everyone, get impeached and demoted to working in the bowels, and [[TooDumbToLive get himself farted out of Frank]].
* ClicheStorm: Apart from the fact that it takes place in the animated premise of a human body, the movie plays up the BuddyCopShow tropes to a tee without much variation.
* CompleteMonster: [[DiseasedName Thrax]] is a [[MonstrousGerms deadly virus]] who is [[FameThroughInfamy obsessed with infamy and making his name known in the medical books]]. To this end, Thrax infiltrates human after human and slowly kills them through an agonizing fever--one of his victims a [[WouldHurtAChild little girl]] who "didn't like to wash her hands"--which comes with the consequence of killing both the human and every living organism inside of them. Upon invading the body of Frank [=DeTorre=], Thrax [[EstablishingCharacterMoment introduces himself]] by burning a cell unfortunate enough to cross him from the inside out whilst humming, and cuts clean through a local crime boss to cow his flunkies into serving him. Thrax sets about murdering whomever comes in his way and burns his own flunkies to death after they suggest incubating, ultimately nearly succeeding in dooming Frank and gloating to hero Osmosis Jones that he intends on breaking his record on Frank's young daughter Shane.
* CultClassic: Generally regarded as a dud with too many unfinished or poorly-realized ideas, it otherwise has a decent fanbase of nostalgic millennials who love it for what it is. The fact that it's one of the few theatrically released 2D-animated features from UsefulNotes/TheMillenniumAgeOfAnimation certainly helps. The movie's creativity with the scenes inside Frank's body have definitely gotten a lot of admiration over the years that even detractors have said those parts mostly work well.
* EnsembleDarkhorse:
** Even among the film's detractors, Leah Estrogen is seen as this for her honesty and caring attitude without being offensive.
** Mrs. Boyd, for being the only relatable human, outside of possibly Shane.
* EpilepticTrees: Due to the fact that he does not act like a normal virus, there are numerous fan theories on what Thrax is.
* EvilIsCool: Even the movie's detractors claim that Thrax was the best part of the movie. He's got a cool design and fashion sense, a terrifying presence, and is just so suave and FauxAffablyEvil.
* FriendlyFandoms:
** With ''Manga/CellsAtWork'', thanks to their similar premises.
** It also has one with ''Film/KangarooJack'' and ''Film/ScoobyDoo2002'' for being WB films that were retooled from adult-oriented films to family-friendly ones.
* HarsherInHindsight: The movie building up Osmosis and Leah as a couple goes down the drain when you put the spin-off show into account where Osmosis and Drix are forced out of Frank and transferred to a different body.
** The already intimidating Thrax becomes much more terrifying in the wake of [[UsefulNotes/Covid19Pandemic another]] deadly cold-like virus.
* HilariousInHindsight:
** [[Franchise/{{Pokemon}} Pikachu]] makes a small cameo, in the form of a plushie being held by a germ. In 2008, a type of retinal protein was discovered and was given the nomenclature of Pikachurin.
** Thrax declaring that "Ebola is a case of ''dandruff'' compared to me!" is made somewhat funnier by the arrival of [=ZMapp=], Ebola's highly tentative cure.
** Mayor Phlegmming has been compared to President UsefulNotes/DonaldTrump thanks to his appearance, policies, and demeanor.
** Tom Colonic has been getting some comparisons to 2020 Democratic Presidential Candidate Beto O'Rourke.
** Creator/WillSmith was originally chosen to voice Ozzy before he turned down due to scheduling conflicts. He would later [[WesternAnimation/SharkTale voice a character in another kids' crime movie]], and [[Film/Aladdin2019 play a blue character in a remake of]] [[WesternAnimation/{{Aladdin}} another animated movie]].
** The animators for this movie would wound up doing the animation for [[WesternAnimation/EightCrazyNights another animated buddy comedy headlined by SNL stars]].[[note]] While ''Osmosis Jones'' was infamously cut down from a PG-13, ''Eight Crazy Nights'' remained PG-13[[/note]] Bonus points for Creator/ChrisRock and Creator/AdamSandler being frequent collaborators.
** This film stars Creator/ChrisRock playing a [[IWorkAlone lone wolf]] CowboyCop who’s treated like a pariah by fellow officers for doing the right thing (with bad results) in the past, and is on the trail of a mysterious killer. 20 years later, he’d be playing a very similar role in ''Film/Spiral2021''.
** The scene where Ozzy gets punched in the face, with the line "Ooh! Why you hit so hard?" becomes hilarious after the same happened to his [[Creator/ChrisRock voice actor]] (courtesy of Creator/WillSmith) at the 94th Academy Awards.
*** Even more hilarious, [[WhatCouldHaveBeen Will Smith was considered for the role of Ozzy before Chris Rock was cast]].
* HoYay:
** Jones and Drix. ''I think I'd like to stay with Jones'' indeed.
** Ozzy and Thrax get a lot of FoeYayShipping, especially with this line from the latter -
--->'''Thrax:''' You know what, Jones? You want this chain so bad, [[DoesThisRemindYouOfAnything Big Daddy Thrax is gonna let you have it.]]
* HollywoodPudgy: There are lines in the script that seem to imply that Shane is overweight. It seems likely that was the original intent and they never changed the script, because the actress they wound up casting is a tiny thing.
* JerkassWoobie: Mrs. Boyd is a very cold and bitter teacher to the point where she'll [[HairTriggerTemper scream her head off at her students]] if they aren't doing their work, and she slapped Frank with a restraining order for simply vomiting on her at the school science fair. But, considering that she and her children were also humiliated after the incident, to the point where they were endlessly teased for it and her daughter Shirley even had to transfer schools and was given the nickname "Hurley", she obviously took out a restraining order on Frank to prevent further humiliation to her and her family, and her becoming such a cold and bitter person was clearly the result of all that endless humiliation--and while she's helping drive the wedge between Frank and Shane, which Frank even protects her by not telling Shane she refuses to make peace with him, Mrs. Boyd still clearly cares about Shane and wants what's best for her (while also probably thinking Shane's life would improve since Frank is seen as a toxic influence).
* JerksAreWorseThanVillains: Frank is deeply unpopular among viewers due to being quite unlikable and lethargic, with the most notable example being his emotionless reminder to Shane on how her mother died. He's actually more disliked than Thrax, who is seen as an [[EvilIsCool incredibly cool villain]] despite [[TheSociopath his utter depravity]], and Mayor Phlegmming, who, unlike Frank, [[HateSink was actually meant to be hated by audiences]].
* JustHereForGodzilla: Most viewers only watch the film for the animated portions, whose exuberance, liveliness and interesting plot have all been praised by critics. The scenes that focus on [[BigBad Thrax]] are considered a highlight by themselves, given that he is far more sinister and [[EvilIsCool cool]] than one would expect a villain from a children's movie to be.
* KarmicOverkill: Frank vomiting on Mrs. Boyd after he made the unwise decision to eat oysters from a science experiment was definitely a grotesque thing to do. But getting slapped with a restraining order and fired from a job over something that was accidental is a bit unfair, to say the least.
* LauncherOfAThousandShips: Thrax. Fans tend to ship him with either [[FoeYayShipping Ozzy]], a SelfInsert, or an OriginalCharacter. And many a {{Fanvid}} maker has made fan edit {{Crossover Ship}}s of him with just about any 2D [=Non/Disney=] animated film character you can think of, the most popular choices being [[WesternAnimation/TheSwanPrincess Odette]] and [[WesternAnimation/SinbadLegendOfTheSevenSeas Eris]].
* MemeticBadass: Ozzy is seen as a hardcore cell after COVID-19 arrived. Helps that his later voice actor Creator/PhilLaMarr mentioned in a Cameo video that "Corona is gonna be a gonna".
* MemeticMutation:
** Thrax escaping the [[BlackBugRoom Subconscious Room]] is used to represent a ScrewThisImOuttaHere reaction.
** "''Osmosis Jones'' tried to warn us!" [[labelnote:Explanation]]Frank’s carelessness leading to getting infected with an unknown and nearly lethal virus, and Thrax’s actions throughout the film (making it seem like Frank only has a common cold until it’s too late), has hit a lot closer to home since the UsefulNotes/COVID19Pandemic started in 2020.[[/labelnote]]
** "Why you hit so hard?" [[labelnote:Explanation]] This line is uttered by Osmosis Jones after he gets punched by one of Thrax's goons. It gained some traction following Jones' voice actor Creator/ChrisRock getting slapped by Creator/WillSmith at the 2022 [[UsefulNotes/AcademyAward Oscars]].[[/labelnote]]
** You can't fuck Osmosis Jones. [[labelnote:Explanation]]A Website/{{Tumblr}} user of the same name made a post explaining how it would be impossible to have sex with Osmosis Jones due to his microscopic size. [[https://youtube.com/watch?v=ipf9MBuurv4 Other users replied]] with suggestions on how it would actually be possible if one tried hard enough. This conversation is often brought up whenever Osmosis Jones is mentioned on Tumblr.[[/labelnote]]
%%** ''"Careful, I'm contagious."'' Explanation?
%%** '''''"EBOLA IS A CASE OF DANDRUFF COMPARED TO ME!"''''' Explanation?
%%** '''''"HAI BABEH!"''''' Explanation?
* MoralEventHorizon: Thrax crosses it by murdering two cells in his introduction with his touch.
* {{Narm}}:
** Uncle Bob's reaction to [[spoiler:Frank getting hospitalized]]. His "crying" honestly sounds like hooting laughter.
** Frank eating a Circus Peanut while trying to have a moment with his daughter about her mother passing away is such a pathetic sight that you can't help but laugh at it, which is also especially not helped by Creator/BillMurray's apathetic performance in that scene. It's often seen as a low point for Bill Murray, who's otherwise a fantastic actor.
* NarmCharm: As the City of Frank collapses, there is a weird parody of the band from ''Film/Titanic1997'' as Frank's body dies, including a performance of "Nearer My God to Thee". Yet, it comes across as a strangely moving homage in a very heartwrenching scene.
* NauseaFuel: The movie takes place inside and around a severely unhealthy and unhygienic person, so it unsurprisingly contains a ton of gross moments. [[NauseaFuel/OsmosisJones Enough to deserve its own page]].
* OneSceneWonder: Creator/RonHoward as Tom Colonic, thanks to his [[ReasonableAuthorityFigure caring attitude as a politician]].
* ParanoiaFuel: There's a lot in this film. Firstly, your body is made up of trillions of fully sentient cells; talking, crying, and living their lives ''within you'' as you live about yours. Every time you cut yourself and blood drips out, that's a couple million people DYING! Also, related to the FridgeHorror, your Mayor (with approval from the City Council) has the ability to take over your brain and make you say and do things beyond your control.
* RealismInducedHorror: Any major outbreak is often going to result in a lot of fans taking Thrax seriously as a threat.
* TheScrappy: Frank is seen as such for being such a despicably unlikable slob. Especially with how he [[TooDumbToLive casually disregards his own health]], his apparent apathy towards Shane's frustration, and Creator/BillMurray's emotionless performance. It doesn't help that the beginning of ''WesternAnimation/OzzyAndDrix'' shows him [[AesopAmnesia going back to his old self-destructive habits]].
* SignatureScene: Frank eating the egg as it switches to the first animated portion of the movie taking place in Frank's mouth, as it was one of the scenes most prominently showcased in promotional material for the movie. This is in addition to how memorably disgusting the scene is, said egg having been previously ''in a chimpanzee's mouth'' and then ''on the ground of the chimp cage''.
* {{Squick}}:
** Frank picks up a hard-boiled egg and eats it. What makes this Squick? The egg has been on the ground in a filthy chimpanzee cage, and before that it was ''in the chimp's mouth''.
** A horror film playing in Frank's movie theater (i.e. a nightmare from his subconscious) involves his daughter marrying his brother.
** One of the songs in the soundtrack, titled "Cool, Daddy Cool" by Kid Rock and Joe C, has lyrics openly talking about underaged girls.
--->''Young ladies, young ladies. I like them underaged, see. Some say that's statutory, but I say it's mandatory.''
* TrailerJokeDecay: Several jokes found in the film are first shown in the two trailers, making them less funny.
* VindicatedByHistory: Even though it got lukewarm reviews when it came out, it gained a loyal following among the nostalgia crowd for the strong animated scenes. It has also gotten fairly popular among those in medical professions for its surprisingly accurate depiction of the human body.
* WhatDoYouMeanItsForKids: Originally, it wasn't, but it was neutered ''just'' enough to fit a PG rating. This apparently didn't apply to the blatant sex references, violent deaths, and extreme gross-out humor. In fact, there was an online game on the website called ''Mystery of the Rash Outbreak'' that has strong language.
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