->''"Fantastic idea for a movie. Terrible idea for a proctologist. Are you going to miniaturize me?"''
-->-- '''The Twelfth Doctor''', ''Series/DoctorWho'': "Into the Dalek"


A plot that involves characters being shrunk to enter someone's body. Usually animated. Travel is often via submarine and scuba variants. Lighting is rarely a problem. Often has a time limit parameter, and at least one scene of just barely squeezing through some sphincter or valve [[SlowDoors as it closes]]. If there's a scene inside the stomach, expect to see either random inedible objects scattered around (even if the character ''isn't'' an ExtremeOmnivore) or food that has been swallowed whole that would normally be too large (such as whole burgers). Sometimes both. Protagonists being menaced by SeekerWhiteBloodCells and/or [[BigCreepyCrawlies giant tapeworms]] (well, giant to ''them'') is also common.

See also IncredibleShrinkingMan. If there are normal-size invaders inside a [[AttackOfThe50FootWhatever giant's body]], then you have been SwallowedWhole. Curiously, giant bodies tend to be [[BiggerOnTheInside filled with large open spaces for movement and even extended travel within]], even if one was swallowed.

Named for the granddaddy of them all, a movie co-starring Raquel Welch, which also spawned its own AnimatedAdaptation. An episode with this plot will usually contain some kind of direct homage to or parody of said film -- a favourite being the infamous ClothingDamage scene. Bizarrely, the titles of such episodes surprisingly often reference ''JourneyToTheCenterOfTheEarth'' instead, with the person's name or a noun that describes them in place of "the Earth".

Not to be confused with the {{funk}}arific song by Lakeside.

Compare and contast with JourneyToTheCenterOfTheMind, GhostInTheMachine, and AnimateBodyParts. If somebody's body just happens to be the {{Adventure Town|s}} ''this'' week, you're probably just flying in a WombLevel.
----
'''Examples:'''

[[foldercontrol]]

[[folder: Anime and Manga ]]

* In episode 10 of ''KeroroGunsou'', Keroro's mouth becomes infested with microscopic, cavity-causing aliens, and a good chunk of the rest of the cast (including a robot duplicate of the sergeant mentally controlled by Keroro) shrinks down and enters his mouth to fight them off.
* In ''Anime/DragonBallZ'', during the fight versus Buu, Goku and Vegeta ([[FusionDance fused together]] as "Vegetto") get absorbed by Buu, and end up travelling through the villain's body so they can rescue their allies.
* Due to some extremely trippy AppliedPhlebotinum, the final battle of the IL arc of ''GetBackers'' takes place inside the opponent's body. Thus, hitting Makubex (who was in there with them...) caused the whole landscape to warp and shake.
* In the third part of ''Manga/JoJosBizarreAdventure'', when Steely Dan implants his microscopic Stand, [[TarotMotifs Lovers]], into Joseph's head, Polnareff and Kakyoin shrink their own Stands to the same size and enter Joseph's brain to battle Lovers.
* ''Anime/GalaxyAngel'' has an episode where the team needs to enter Volcott's body because of some strange thing that make him change his body into several crazy stuff. Mint got haywire and it turns even crazier, which in the end result in Volcott turning into a baby.
* ''Anime/{{Doraemon}}'' features the title character and Nobita going inside Shizuka's body to retrieve a diamond she accidentally swallowed.
** Somebody parodied this on 3D Movie Maker (with the Doraemon Expansion Pack) where Shizuka poops out Nobita, Doraemon, Gian and Suneo, along with green slime. (She didn't poop out the diamond, though.)
* The JosephLai MockBuster psuedoanime ''SpaceTransformers'' is about a mecha and its young pilots entering the body of a woman... who has a small galaxy inside her body.
* In ''LightNovel/KyouranKazokuNikki'', Kyouka turns the family into a microscopic virus-fighting squad and takes them inside Ouka's body.
* In one episode of the anime of ''VideoGame/ParappaTheRapper'' ("Did You Say You Didn't Sleep?!"), Parappa's friend PJ gets infected by a virus, which causes him to grow into [[AttackOfThe50FootWhatever a giant]] every time he eats. This causes Parappa and his friends to get absorbed into his body and get rid of the virus in order to turn him back to normal.
* ''Anime/{{Gintama}}'': The Tama Quest Arc which is also a parody of the ''Franchise/DragonQuest'' game franchise.

[[/folder]]

[[folder: Comic Books ]]

* In ABCComics' ''ComicBook/TomStrong'', Tom and his gorilla sidekick Solomon have to shrink themselves to enter the body of the malfunctioning robot butler Pneuman (which is more complex than it sounds because Pneuman had originally been a Steampunk robot in the 1890's and had been upgraded continuously right into the 21st century, so his innards contained everything from gears to vacuum tubes to atomic reactors to nanites).
* There was a comic, probably from DC's silver age, in which TheAtom (Ray Palmer) had to enter the body of a patient to fight an infection. (Given his powers, it would be somewhat surprising to learn that that's the only time that happened.) Then ''Superman'' had to get himself shrunk and go in after him when [[spoiler:the observers on the outside figured out that the microscopic creatures he was trying to get rid of were actually themselves fighting the infection rather than causing it]].
** There's a similar story in a Justice League comic (I think #41, before Tower Of Babel) where the whole JL get shrunk by The Atom and enter someone's body. They lose their powers for some reason and are imprisoned by a race of tiny aliens.
* ''Comicbook/{{Teenage Mutant Ninja Turtles|Mirage}}'' volume 4 featured a variation similar to ''Futurama'''s: instead of shrinking down, the turtles sent millions of mentally-willed [=NanoTurtleBots=] into April O'Neil's body, which had been infected by millions of [=NanoBaxterBots=].
** Later they have a straight example, going into April's sister's body to fight off "alien cancer".
* In [[http://coa.inducks.org/s.php?c=I+TL+1916-B this Disney story]], Gyro shrinks DonaldDuck (and a submarine) so he can go inside Uncle Scrooge and save his life.
* ComicBook/AntMan of Comicbook/TheAvengers got to do this when he had to get inside his teammate TheVision in order to fix a malfunction inside him, during ComicBook/TheKreeSkrullWar. It was done again, as a MythologyGag, in HeroesReborn.
** He did it again in ComicBook/NewAvengers to retrieve a device on Luke Cage's heart, bringing Comicbook/DoctorStrange with him.
* The Silver Age {{Supergirl}}, when she was affected by three Red Kryptonite meteors, got shrunk to microscopic size, which she used to her advantage to take care of some infectious viruses that were inside Dick Malverne's adoptive father.
* In ComicBook/TheSimpsons comic, Mr. Burns has become ill from suppressing his need to burp for decades. To undo the blockage that built up in his system, Burns' scientists plan to drop a shrunken submersible into his body. Though the pod can be remote controlled, they still need a pilot in case of an emergency. Since even 'an anthropod will do' Homer is selected.
* In Archie's ''ComicBook/SonicTheHedgehog'' #33, Sonic must shrink down and enter Rotor's body to fight off robotic germs.
* In a later issue of [[ComicBook/RomSpaceknight Rom: Spaceknight]], Rom and Starshine reduce themselves by the use of Ant-Man's technology to submicroscopic size so they can enter the body of an ant and find a way to defeat a semi-mystical plague.

[[/folder]]

[[folder: Film ]]

* ''Film/FantasticVoyage'', [[TropeNamer obviously]]. The scientist who perfected the technology [[SovietSuperScience in the USSR]] is wounded after defecting and has a bloodclot that can't be operated on externally, so a team goes in on mini-submarine.
* In a rare ''permanent'' case, the film ''OsmosisJones'' and the cartoon series it spawned were about cells, germs and viruses living inside a human being as if they were citizens of a city.
* ''Film/{{Beetlejuice}}'': The Maitlands meet Beetlejuice in Adam's model of the town.
* The movie ''Film/{{Innerspace}}''.

[[/folder]]

[[folder: Literature ]]

* In one ''Literature/{{Animorphs}}'' book, several members of the team chase some really tiny aliens inside Marco's body with the help of a convenient shrink ray. This is made more complicated by the fact that Marco can shapeshift, and everyone is nearly crushed to death when he turns into a cockroach.
** Note that Marco's morphing was dangerous to the Helmacrons too, not just to the Animorphs. So [[IdiotPlot if they had thought of it]], they wouldn't have had to go to all the trouble of going inside Marco, they could have just had Marco morph repeatedly, as long as it took to get the Helmacrons to surrender and come out of his body. Naturally, though, that wouldn't have made for a dramatic story...
* In the fifth novel in the ''YoungWizards'' series, ''Wizard's Dilemma'', Nita and Kit travel into the body of Nita's mother, though they do so in a [[MetaphysicalPlace metaphysical]] manner rather than by shrinking themselves, with her body's metaphysical representation taking on the appearance of New York City.
* In ''Literature/TheThirteenAndAHalfLivesOfCaptainBluebear'' the main character that gives the book its name must venture through a giant's brain in order to get to the other side of a mountain chain, as the giant has [[strike: died]] fallen asleep and its head is blocking the pass through the mountains.
* Besides the film novelization that he wrote (which is in itself notable for being a movie tie-in that's still in print ''over forty years after the movie was in theaters''), Creator/IsaacAsimov wrote a SpiritualSequel novel in the 1980s called ''Fantastic Voyage II: Destination Brain''.
* ShowWithinAShow version: in ''Literature/DreamPark'', one of the park's many popular attractions is the Mr. Digestion roller coaster.
* The story "The Space Cow" inverts this; a normal-sized veterinarian enters a gigantic alien organism to attempt to diagnose its apparent illness. [[spoiler:The animal is perfectly healthy, it's just lethargic because [[BizarreAlienBiology its young are ready to leave its stomach]] and begin independent living.]]
* In ''AWindInTheDoor'', Meg Murry and several other characters shrink to microscopic size to enter Charles Wallace's mitochondria and save him from the [[ArtisticLicense rebellious farandolae]] destroying him from the inside.
* In ''JourneyToTheWest'' (and by extension most adaptations thereof), Sun Wukong shrinks himself and enters Princess Iron Fan's body by hiding in her soup.

[[/folder]]

[[folder: Live Action TV ]]

* There's a ''Series/SabrinaTheTeenageWitch'' episode where a live action version is done -- Sabrina enters Libby's brain.
** Later, Sabrina went inside ''herself'' to make room in her heart for a new beau.
* ''[[{{Series/DoctorWho}} Doctor Who]]'':
** In the [[{{Creator/TomBaker}} Fourth Doctor]] serial ''The Invisible Enemy'', miniaturized clones of the Doctor and Leela enter the Doctor's body to fight a virus. [[spoiler:They fail, but clone-Leela's dissolving corpse imbues the Doctor with immunity.]]
** In the [[{{Creator/PeterCapaldi}} Twelfth Doctor]] episode "Into the Dalek", the Doctor, Clara and some soldiers enter the shell of a malfunctioning Dalek.
* Another live-action example is an ep of ''HomeboysInOuterSpace''.
* The premier episode of the series adaptation of ''Series/HoneyIShrunkTheKids'' did this ''accidentally'' when the family's fully submersible (just in case) minivan wound up inside Grandpa. They did some impromptu cholesterol removal with the laser windshield de-icer, prompting the mother to ask "[[ReedRichardsIsUseless Why aren't we richer?]]"
* In one of the more clever ''LostInSpace'' episodes, Will Robinson and Dr. Smith find a severely malfunctioning robot who has become a giant due to his problem. The two have to physically enter the robot's body to fix him. However, the major complication is that they know that the second they are successful, the robot's body would start shrinking to normal size and they would have only seconds to escape before they are crushed. Naturally, the pair escape just in time before it was too late.
* There's an episode of TheMightyBoosh called "Journey to the Centre of the Punk", when punk Vince is infected with a Jazz Virus, and Howard and Lester are shrunk in order to destroy it. This is probably the strangest one ''ever'', especially the antibodies singing a song with Howard while he's trying to convince them he's their friend.
* [[DiscussedTrope Joked with]] in an episode of ''Series/{{House}}'' by Taub and Kutner.
* ''TheMiddleman'' episode "The Clotharian Contamination Protocol" had Wendy go inside [[RidiculouslyHumanRobot Ida's]] body to stop nanobots from making her explode. The snarky subtitles [[LampshadeHanging referred to it as]] "Like ''Film/FantasticVoyage''. Or [[DieHardOnAnX Die Hard in an Android]]".
* In WizardsOfWaverlyPlace there's an episode where Mason, [[spoiler:Alex's ex boyfriend]] swallows Dean, [[spoiler:Alex's other ex boyfriend]].
* The episode "The Flower where Evil Lies" from ''Series/UltraSeven''
* In the cartoon segments of ''TheAquabatsSuperShow'', the band shrinks down to infiltrate Jimmy the Robot's body in order to rid him of his parasites that make him malfunction.
* In the upcoming ''Series/MrYoung'' episode ''Mr. Heart'', Adam and Derby shrink down and entry Echo's body to fight a flu virus and allow her to go on a date with Adam that same day. Of course, they do have to find a way out again...
** After they eventually manage to escape, the three of them are then accidentally shrunk down and unknowingly eaten by Slab. [[spoiler: The episode ends with Slab taking a trip to the "little boy's room"]].
* Disney's ''Series/MightyMed'' has an episode where an envious Kaz uses a shrinking ray on Oliver for revenge on "stealing" his crush. It just so happens that a superhero with metallic skin has fallen ill and, as his skin makes x-rays and injections impossible, the only way to find out what's wrong is to send Oliver inside him. It turns out to be the superhero's arch-enemy, who had shrunken himself down to destroy the hero from the inside.
* In ''Series/CosmosASpacetimeOdyssey'', Neil shrinks the Ship of the Imagination down to cellular level to fly into a brown bear's bloodstream, eventually traveling to the ovaries where he can explain how genetic mutations gave rise to polar bears.

[[/folder]]

[[folder: Music ]]

* The song ''Samut and the Dragon'' (found in ''Peter Alsop and Bill Harley In the Hospital'') details a young boy with cancer who uses imagery to help his body heal. Every evening he dresses up like a knight and rides a white stallion into his own body, "by the bloody steaming rivers... through the mighty sinew forest, under tendon trees and bone," until finally he finds the cancer, a dragon, and uses his "healing sword" to strike it down, leaving his body to heal in peace. Of course, the dragon's always back by the next evening, but one hopes it's getting a little weaker.
* The music video for the song ''Special K'' by Music/{{Placebo}} acts as a kind of homage to the film ''Fantastic Voyage''. The music video takes place at an unspecified laboratory where the lead singer, Brian Molko, is shrunk and sent into the body of drummer Steve Hewitt, in order to locate and destroy a clot somewhere in his brain.

[[/folder]]

[[folder: Radio ]]

* In Series Three of ''Radio/OldHarrysGame'', Satan and the Professor take a journey into Scumspawn's brain, discovering it to be a wide empty space, containing only tumbleweed and lumbering demon-thoughts. The title of this episode does somewhat reference the TropeNamer- 'The Reasonably Fantastic Journey'.

[[/folder]]

[[folder: Video Games ]]

* ''LaMulana'': [[spoiler: The Ruins of La-Mulana are the Mother's body, and the true form of the final dungeon is a hybrid ruin/WombLevel]]
* The text adventure game version of ''VideoGame/TheHitchhikersGuideToTheGalaxy'' included a sequence where Arthur would find himself exploring his own brain.
* In one of the missions in ''EliteBeatAgents'', the EBA enter a track star's body in order to encourage his immune system (anthropomorphized as a nurse) in its battle against a rather nasty virus.
** In the [[OsuTatakaeOuendan original Japanese game]], the Ouendan squad helps antibodies fight off what appears to be food poisoning in a musician.
* In Irem's shooter ''X Multiply'', the spaceship X-002 gets miniaturised and injected into a space colonist's body to defeat an alien virus. You even get to see the X-002 coming out of the tip of a syringe at the very beginning of the game.
* Done twice in ''{{Okami}}''. First, a shrunken Amaterasu has to enter the Emperor's body, through his mouth, to stop whatever it is that is making him exhale a noxious gas. A much longer trip involves a full-sized Ammy leaping down the gullet of the Water Dragon and exploring its innards, [[spoiler: causing such wounds in the process that the Dragon dies from internal bleeding]].
* The UsefulNotes/ZXSpectrum game ''[[SerialNumbersFiledOff Blood And Guts]]'', in which a miniaturised character must collect bits of a submarine and reconstruct it in the brain in order to escape through the eye, all the while using a laser to fight infections, random white blood cells to clear growths, and collecting red blood cells for oxygen. Eventually Quicksilva decided to abandon all pretense and re-released the game as ''Fantastic Voyage''.
* There is a level in ''DevilMayCry 3'' which takes place in Leviathan's body. Leviathan isn't big enough to hold all of that space, but his in-game profile says that his body serves as a gateway to the "jealousy hell" (in a nice ShoutOut to Leviathan's traditional role as the patron demon of envy).
* In ''VideoGame/{{SaGa 2}}'', the party must travel inside Kai in order to fight off micronized soldiers of Ashura and extract the Magi from Kai. [[spoiler:While this saves her life, it also means that she can't heal you afterwards since the Magi granted her healing powers.]]
* Tanzer serves as this kind of dungeon in ''VideoGame/{{SaGa Frontier}}''. You are swallowed by him randomly.
* The last part of ''SpaceQuest 6'' involves series hero Roger Wilco being sent into the body of his friend/love interest Stellar, to save her from being killed/possessed by nanites. Although Roger has a shrunken shuttlecraft for part of the voyage, much of the action takes place on foot; many of the puzzles involve figuring out how to navigate through Stellar's labyrinthian innards. Among other things, he uses digestive juices to break open a medicine capsule, carries out an improvised balloon angioplasty (using alveoli) to clear a path through a blocked glandular duct, rides a tapeworm through the small intestine to avoid being digested, and jabs her brain with a paper clip to trigger a debris-dislodging cough.
* The plot of ''[[VideoGame/MarioAndLuigiBowsersInsideStory Mario & Luigi: Bowser's Inside Story]]'' has the brothers working with Bowser after the latter ended up sucking them up inside of him.
* ''[[GearsOfWar Gears of War 2]]'' has Delta Squad swallowed whole by a [[spoiler:giant riftworm that's been sinking human cities]]. Marcus and the gang have to kill it from the inside out using ''freaking chainsaws.''
* Bodyworks Voyager was an educational game from 1994 that was set TwentyMinutesInTheFuture and involved a crack team of commando-doctors trained to pilot fighter ships that were shrunk and injected into a patient's body, where your task was to shoot germs. Considering this came out years before TraumaCenter, some of the bugs were just damn HARD.
* The FullMotionVideo game ''VideoGame/{{Microcosm}}'' was a space shoot-'em-up with this plot.
* Amiga game ''VideoGame/{{Vaxine}}'' had you fighting diseases within different organs of the body, only the playing field was an infinite chessboard and the diseases were represented by bouncing balls.
* Midgame in ''VideoGame/FinalFantasyII'' you are swallowed by Leviathan and must fight your way out of him.
* ''Rex Ronan: Experimental Surgeon'' for the SNES.
* {{Gradius}} series has [[GaidenGame Life Force]] for the NES/Arcade, which is set inside a [[PlanetEater planet-devouring]] EldritchAbomination named Zelos.
* ''VideoGame/KingdomHearts'' has a Monstro WombLevel, which has more anatomical detail then the [[Disney/{{Pinocchio}} film it's based on]].
* For some unknowable reason (wanting to make good use of the textures?) ''BreathOfFireII'' is in love with this setting: over the course of the game, Ryu journeys inside a whale (to kill the monsters nesting inside of it and wake it up), a tree (to cure its senility), and an overweight queen (to exterminate the calorie demons inside her organs.)
* The UsefulNotes/{{Intellivision}} game ''Micro Surgeon'' had this as its plot.

[[/folder]]

[[folder: Web Animation ]]

* Seppuku's episode in the World of the Damned storyline of ''BananaNanaNinja'' has him [[IncredibleShrinkingMan shrinking down]] and swimming through his opponent's intestines and bloodstream.

[[/folder]]

[[folder: Web Comics ]]

* Done in ''Webcomics/TheNonAdventuresOfWonderella'' [[http://nonadventures.com/2007/12/15/tumor-has-it/ here]].

[[/folder]]

[[folder: Western Animation ]]

* ''WesternAnimation/AquaTeenHungerForce'', "Unremarkable Voyage": After Meatwad swallows an experimental computer chip, Frylock shrinks himself to go in and get it. Thanks to a few screw ups, both he and a miniturized Carl eventually wind up inside Master Shake. They then have to beat their way out of Shake's eye, killing him in the process. [[NegativeContinuity No worries though.]]
* On ''WesternAnimation/CaptainPlanetAndThePlaneteers'', the shrunken Planeteers battle microbes from polluted water inside Kwame after he accidentally drinks them.
* In an episode of ''CatDog'', Cat goes inside his and Dog's own body after Cat eats Dog's pet fish. Very, very confusing if you haven't seen it.
* ''WesternAnimation/DangerMouse'' has an episode where DM and Penfold use Baron Greenback's shrink ray to follow the villain inside Colonel K. to defeat the toad's terrible plot.
* ''WesternAnimation/FamilyGuy'': Stewie shrinks himself and enters Peter's body to prevent his parents from reproducing. Apparently all sperm are their potential human counterparts flying around in fighter jets. Stewie also meets a comrade in sperm form who shares the same sadistic tendencies as Stewie. He actually gets born in a later episode after Peter donates sperm.
* ''WesternAnimation/{{Futurama}}'', "Parasites Lost", although with a twist: Zoidberg and co. are sending miniature robot replicas of themselves inside Fry. Gives Leela (well, a miniature thereof) the opportunity to slice and dice them up without any long-term ramifications. Farnsworth's scientific explanation as to why they don't shrink themselves:
--> '''Prof. Farnsworth:''' That would require extremely tiny atoms, and have you priced those lately? I'm not made of money! Leave me alone!
** The "tiny robots" method also allows for an unusual take on the trope - later in the same episode, Fry creates his own tiny robot, thus effectively allowing him to go inside ''his own body'' (though this was earlier done on ''Doctor Who'', with clones instead of robots -- see above example).
* ''WesternAnimation/KidsNextDoor'', "Op SPROUT," in which Numbuh Four accidentally eats a Brussels sprout, and Numbuhs One, Two and Five shrink themselves to retrieve it.
* Inverted on a later episode of ''WesternAnimation/TheRenAndStimpyShow''; a boy genius inflates Stimpy's body with a bicycle pump to ridiculous proportions, so that Ren can enter his body and find out why Stimpy is acting even stupider than usual.
* ''WesternAnimation/{{Rugrats}}'', "The Inside Story": Tommy and co. go inside Chuckie to retrieve a watermelon seed, though in keeping with the relatively mundane setting, it's AllJustADream.
* ''WesternAnimation/{{Sealab 2021}}'', "Craptastic Voyage": When Captain Shanks refuses to get treatment for a brain tumor because of his religion (a thinly-disguised parody of Christian Science), Stormy, Quinn, and Debbie Dupree shrink themselves to microscopic size and travel through Shanks' body to deal with it themselves. Subverted in that the episode's mostly ''Franchise/StarWars'' parodies, not ''Film/FantasticVoyage''.
* On an episode of ''WesternAnimation/TinyToonAdventures'', Buster, Babs, and Calamity shrink to enter Plucky's head and examine his brain to watch his fantasies.
* The plot of one of ''WesternAnimation/TheSimpsons'' Halloween short. Marge references LatexSpaceSuit when she asks why her suit is so flatteringly cut. Homer replies, "But Marge, that's what turns a Mediocre Voyage into a Fantastic Voyage!"
* ''WesternAnimation/ReBoot'', "The Great Brain Robbery": Megabyte miniaturizes a mercenary named Mouse and his flunkies Hack and Slash and sends them to probe secrets from Bob's brain. Except they accidentally end up in Enzo's body instead, and Bob goes in after them.
* Several WesternAnimation/LooneyTunes shorts inverted this, by sending BugsBunny or another character running over and through the body of a giant as if it were a building (including pulling shades down over the giant's window-eyes). These no doubt influenced the ''RenAndStimpy'' version above.
** In one episode of the ''WesternAnimation/{{Beetlejuice}}'' cartoon, BJ got a bad case of EasyAmnesia after being hit by a falling satellite, and a psychiatrist shrinks himself, Lydia, and a duplicate of Beetlejuice so they can enter the original BJ's body, work their way to the brain, and fix the problem.
* In the "Mundane Voyage" episode of Ralph Bakshi's ''MightyMouseTheNewAdventures'', Mighty Mouse is miniaturized and sent into the President's body.
* ''TheMagicSchoolBus'' once took a tour through the human body in one of the books that spawned the TV series, and then ''five'' times in the TV series: Arnold was the "victim" in the book and the show's adaptation of it, with him accidentally ingesting the shrunken bus while eating a snack, while Ralphie and Ms. Frizzle had their turns as well, to investigate the body's immunity system, and muscular systems respectively. Then they wound up going inside Arnold ''again'' to figure out what had made his skin turn orange. Finally, Arnold cousin Janet gets her turn when the class goes inside her nose to study smell. There was also a computer game where you- you guessed it- go inside Arnold. Poor kid.
* ''WesternAnimation/SouthPark'' did a twisted parody of this trope, in which a gerbil named Lemminwinks had to find his way out of Mr. Slave's ass. And then it happened again with ''Paris Hilton''.
* ''InvaderZim'' miniaturized himself and his spaceship to go invade Dib's brain after Dib manages to get proof of Zim's alienness in the episode "Nanozim".
** Dib then swallowed a nanobot and had Gaz remote control it, eventually leading to [[spoiler: Dib's robot and Zims robot fighting near Dib's brain.]]
* Used in an episode of ''WesternAnimation/TeenTitans'' where Beast Boy turns into a bacterium to fight a computer virus that has taken over Cyborg.
* An episode of the '90s ''WesternAnimation/IronMan'' cartoon does this; Hawkeye's spine is injured in a fight, and Tony has a technological fix but no way to safely insert it. So naturally he goes for hand-delivery. This is further complicated when a similarly-shrunken Ultimo tags along.
--> "You're giving him a heart attack!"\\
(Tony is trapped in a ventricle) "Yeah, and it's me it's attacking!"
* The titular character of ''{{Chowder}}'' once ate a really sour fruit that made his lips pucker so tight that he created a portal that sucks himself into his own mouth. He then had to get rid of the pieces of fruit in his mouth, led by "Lord Souron", with sweets and a musical number to get back.
* There is an episode of ''WesternAnimation/CowAndChicken'' called Journey to the Center of Cow where Chicken was accidentally swallowed by Cow. This is a rare example of when some one was not shrunk.
* The ''WesternAnimation/LiloAndStitchTheSeries'' episode "Poxy", where they must chase after an experiment of microscopic size that is inside Pleakley's body.
** Also when Stitch and Jumba enter Lilo's dream to rescue her from Remmy, who would trap them inside Lilo's nightmare.
* ''TheAdventuresOfJimmyNeutron'' where he and Sheen go inside Carl's body in order to get DNA for Jimmy to make a cure to an illness. Of course, there is then the trouble of how you get out...
** But they soon decide that they should make Carl sneeze them out.
* ''WesternAnimation/DextersLaboratory'' where he goes inside Dee Dee's body to combat a cold she's having. He ends up in the dog instead.
* ''PhineasAndFerb'': On the episode "Journey To The Center of Candace", When Isabella's dog Pinky eats her sash, the boys try to go inside and retrieve it, but [[ExactlyWhatItSaysOnTheTin are accidentally eaten by Candace]].
* The ''WesternAnimation/BatmanTheBraveAndTheBold'' episode "Journey to the Center of the Bat!", starring Aquaman, the Atom, and the cutest lymphocyte EVER.
* A episode of ''MuppetBabies'' had Kermit, Piggy, Gonzo and Skeeter use their imaginations to shrink down to germ-size and give Scooter's bumbling immune system a hand when he catches a cold.
* In the season finale of ''TheSecretSaturdays'', the final battle between [[spoiler:Zak and Argost takes place inside the body of the super cryptid [[strike: Kur]] fake Kur.]]
* In the finale of ''TransformersReturnOfConvoy'', the Battlestars are swallowed by Star Giant and have to fight their way out from within.
** ''WesternAnimation/TheTransformers'' has the episode "Microbots," which features Bumblebee, Perceptor, and Brawn shrinking down to enter Megatron and remove a power-enhancing crystal.
** The Annual issue of ''ComicBook/TransformersMoreThanMeetsTheEye'' opens with a group of Autobots led Rodimus entering Ultra Magnus to destroy a colony of lethal [[{{Nanotechnology}} nanocons]].
* ''PinkyAndTheBrain'' did this in order to foil an intelligibly-enhanced cat's DanceSensation plot from being carried out properly by a band, by shrinking themselves and letting themselves get ingested by one of the band members. Unfortunately for them, they get eaten by the completely wrong guy, but they made the best of the situation by having the guy stand in for them.
** Done also in the comic book, in which they attempted to enter the President's brain, but ended up inside the First Dog.
* In a tongue-in-cheek episode, ''SamuraiJack'' once had to enter an ailing dragon's body to cure its devastating flatulance.
* ''TheFairlyOddparents'': "Tiny Timmy" - Timmy shrinks down to microscopic size to do a biology report and ends up inside Vicky.
* Done in ''MonaTheVampire'', in the episode "The Sam n' Ella Infiltration", to enter the body of someone who is sick.
* ''WesternAnimation/QuackPack'' had an episode where a germ-loving scientist invades Donald's body, with Huey, Louie and Dewey being shrunk and sent inside their uncle in order to stop him.
* ''RexTheRunt'', "Holiday in Vince": The dogs voyage into Vince's brain in a shrunken submarine in an attempt to cure his Random Pavarotti Disease (he frequently blurts out short bursts of opera). Eventually they find his tuning knob and retune him to Radio 4 (so he now blurts out gardening tips and the shipping forecast instead).
* [[InvokedTrope Invoked]] and lampshaded in ''WesternAnimation/TheVentureBrothers'' episode "The Diving Bell vs. the Butter Glider". For some reason, Doctor Venture is paralyzed, and they can't use an MRI because there's too much metal in his body, so the logical solution from Billy Quizboy is to get a submarine, shrink it down, and go inside to find the problem. Which turns out to be [[spoiler:a clot in Doc's bloodstream caused by a previous shrunken submarine piloted by previous clones of Hank and Dean, whose skeletons are still there]].
* ''WesternAnimation/GodzillaTheSeries'' had Nick and Monique venture inside Godzilla Jr / [[FanNickname Toonzilla]]. For obvious reasons, shrinking wasn't required.
* [[TotallySpies Sam, Alex and Clover]] shrunk down to the size of microbes to fight a trio of villains inside Jerry's brain.
* [[SpongeBobSquarePants SpongeBob]] and Patrick once entered Squidward's body in order to remove a clarinet reed stuck in his throat. Unfortunately, after completing the task, Patrick accidentally made them re-enlarge while still inside Squidward. While he didn't burst, he did swell up big time from having a full grown submarine inside of him.
* Happens in the episode of ''WesternAnimation/{{Arthur}}'' where Buster Baxter gets asthma.
* In one episode of ''WesternAnimation/{{Gawayn}}'', Gwendolyn and Roderick have to travel inside the body of a dragon to kill the germ causing its acid reflux.
* ''WesternAnimation/DexHamiltonAlienEntomologist'' has an episode where the crew have to travel into the body of sick SpaceWhale in order to cure it.
* WesternAnimation/UncleGrandpa once shrunk himself and Pizza Steve to get inside a kid's brain and make him better at video games.
* {{The New Adventures of Huckleberry Finn}} has an episode ''The Mission of Captain Mordecai'' where the three main characters, Huck Finn, Tom Sawyer and Becky Thatcher get swallowed by a giant whale while trying to escape a mad Ahab-like sea-captain who was trying to force them to be his new crew in his mission to kill said whale. To make matters worse, the giant whale also swallows the captain when he falls overboard while trying to harpoon it, and the rest of the episode deals with the young trio trying to evade the murderous captain while endevoring to find a way out of the beast, which they finally do by climbing out its blowhole, the whale helping them along by blowing them out.
* In the ''WesternAnimation/{{Regular Show}}'' episode ''Cool Cubed'', Thomas drinks a slushie which gives him extreme brain-freeze, and Mordecai and Rigby are sent into his body to thaw his brain out.
* One of the many sketches from WesternAnimation/TwoDTV sees Tony Blair in hospital suffering from an unknown heart condition, prompting the NHS to send a shrunken team of scientists into his body to resolve the problem...at least, that was the plan until John Prescott steps on them. Cue Plan B, where Prescott, David Blunkett (and his guide dog), Jack Straw and Tony's wife Cherie are sent in their place. [[spoiler: Turns out that a miniaturized Gordon Brown is the one causing Tony's heart problems, in his latest attempt to become Prime Minister.]]
* One episode of the ''WesternAnimation/MickeyMouse'' series of 2013-'14 is called ''WesternAnimation/DownTheHatch'', in which MickeyMouse and {{Goofy}} are accidentally miniaturized by a ShrinkRay and then are inadvertently swallowed by DonaldDuck. They explore his body, but when he learns they are in there, the duck tries all he can to get them out. [[spoiler:In the end, as the shrinking effects wear off, Mickey and Goofy emerge from Donald by way of [[WhaleEgg a giant egg]], [[ArtisticLicenseBiology laid by Donald, a]] ''[[ArtisticLicenseBiology male]]'' [[ArtisticLicenseBiology duck!]]]]
* This also forms the plot of a ''WesternAnimation/CaptainNTheGameMaster'' episode, in which all the heroes other than Captain N shrink down to enter his body to help him fight off a disease.

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[[folder: Other ]]

* [[Ride/DisneyThemeParks EPCOT]] used to have a simulator ride called "Body Wars" based on this plot... until they closed down the entire pavilion that used to host it.
** There was also a half-FantasticVoyagePlot, half-JourneyToTheCenterOfTheMind attraction in the same pavilion, called "Cranium Commandos."
** Preceding both of them is the former Disneyland ride [[http://en.wikipedia.org/wiki/Adventure_Thru_Inner_Space Adventure Thru Inner Space]].
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