Mariana: A candiru, a vicious parasite will swim up the urine into your pau.
Beck: Swim up my what?
Mariana: Your pinto. It'll swim up your ding-dong. And once it gets in, you can't get it out.
Beck: [stammers] Well, then what?
Mariana: They have to amputate.
Beck: [closing his pants really tight] Not this boy's pinto. Uh-uh. Not today!
A creature basically forces all of itself into someone else, but through an established opening of the body (as in naturally, not a cut or piercing), even if it's not really an opening (like the navel). It could be the mouth (do not confuse with Force Feeding, but it can overlap with Attack the Mouth), the nostrils, the ear, or through orifices below the belt. Pores could even count.
Can be very strong Nightmare Fuel due to this being a pretty potent Primal Fear, even and especially when it's used in some really odd Hentai (remember Rule 34, boys and girls). Still, do not read the examples unless you want to be really squicked.
Sometimes an orifice evacuation implies that is how it came in, even if that isn't stated.
Not to be confused with Alien Invasion (although these can overlap).
- In the DVD remake of one episode of Bakemonogatari, an invisible snake-like oddity tries to force its way down Nadeko's throat.
- In Basilisk, one of the ninjas from the Iga clan, whose power is to turn into a slug-like thing by contact with salt, kills a ninja from the rival Kouga clan by jumping in his mouth, inside his throat and breaking his neck.
- Dragon Ball:
- In Dragon Ball Z, one of the first acts Super Buu commits after being formed is to turn entirely into pink goo, force himself down the throat of one of the Earthlings that shot Fat Buu's dog and expand, blowing the guy apart from the inside. He tries it again later against Vegetto, who responds by beating the crap out of Buu from the outside.
- In Dragon Ball GT, Baby possesses Vegeta while he's powering up by reverting to his liquid metal state and enters his body through his pores.
- This is done constantly to poor Sakura (with a pit full of crest worms) by her adoptive grandfather as part of her "training" as a mage. It's explicitly said that they enter her body through her vagina, and she had to endure said training from age 5 to 16.
- The same goes for her adoptive uncle Kariya, who is also quite "intimate" with the aforementioned worms. The scene in which he has a remarkably phallic worm forced down his throat is probably the most graphic Orifice Invasion of the series. Zouken even says that this worm in particular took Sakura's virginity.
- Getter Robo has the Invaders, a race of Eldritch Abominations who can invade people's bodies if they so much as bleed on them. Though most of the time they prefer to just dive into people's throats, or simply rip a hole in their torso and use that.
- In the manga version of Ju-on, this is how Kanna meets her end when a bunch of possessed cats enter her mouth and tear her jaw off.
- This is how the larval form of the entities in Parasyte take control of their hosts, usually entering through the ear of a sleeping person to get at the brain. When the protagonist falls asleep with headphones on, his symbiote tries getting in through one of his nostrils instead, which causes him to wake up prematurely, so it has to settle for burrowing into his arm. He can see it under his skin trying to travel up to his head, so he ties his headphone wires tight around his arm to keep it in place, screwing up the transformation process, so he and it end up Sharing a Body instead of it taking over completely.
- Medusa in Soul Eater possesses first a dog, then an innocent girl in the suburbs this way, by turning into a snake and slithering into their mouths. She also does this with the snakes she controls instead of herself: if she can get something into an entry point to a body, she can send in hundreds of snakes which let her track it wherever it goes and can rip it to pieces whenever she tells them to.
- Tokyo Ghoul: During Kaneki's ten-day period of captivity at the hands of Yamori, one of the various tortures Yamori inflicts on him is stuffing a live centipede in his ear. After breaking free from his restraints and beating Yamori into submission, Kaneki stops just long enough to pull said centipede out.
- During the penultimate battle of Yo-kai Watch: Shadowside, one of the Shinma, the Big Bad's shadowy minions, forces itself down Micchy's throat to possess him. It succeeds, albeit briefly, as Micchy is rendered unconscious seconds later, forcing the Shinma to leave his body. The same thing later happens to Jibanyan, although the viewers are spared the gory details this time around.
- Yu-Gi-Oh! ARC-V: The Doktor uses parasite bugs to brainwash the Bracelet Girls; the parasite invades the victim's ear and latches onto their brain and infect the victim to make them the Doktor's puppet. The Doktor also tries it with Yuya, but the darkness inside him causes the parasite bug on his brain to burn to ashes.
- 52 answers a question no one ever asked before: can orifice invasion of a robot be made to look horrific? The answer? Dear Nicolas Cage, yes.
- Guardians of the Galaxy (2008): Moondragon gets a baby Eldritch Abomination in the face, which enters her via the nose. Rocket Racoon, who is a witness, mentions hearing the sound of bones breaking as it forced its way inside.
- Defied in Hack/Slash. A fetal Slasher with a knife attempts to crawl into Cassie Hack's vagina while she's at the gynecologist's office. Cassie, of course, takes exception to this.
- In Marvel Zombies Return, the Zombie heroes are transported to a parallel universe similar to theirs before the plague. While searching for a cure, Zombie Spider-Man runs into the Sinister Six, who confuse him for their version of the hero. They are extremely and understandably shocked when Zombie Spidey gives in to his hunger and starts killing and eating them. Since his sand-like body cannot feed him, he leaves Sandman alive, who escapes. Later, he runs into his universe's Spider-Man, who, unaware of the situation, jokes around normally. Not realizing there are two Spideys, this sends Sandman into a fit of rage, reasoning that Spider-Man clearly no longer cares and rather than be converted into food he decides to kill the hero, by forcing himself into Spidey's mouth and exploding his body from inside in a rather gruesome (if bloodless) manner.
- The image example for this trope comes from The Piper #2 by Zenescope comics. The woman in question (Sandra) just had a poisonous snake slide into her mouth after putting her lips on a french horn's mouthpiece, all thanks to the Piper playing his lethal song outside her room in behalf of Sean due to her beating the crap out of Sean for her buddies over him having recorded a tape, then getting away with it. She dies.
- A (relatively) innocent example happens in PS238 when Polly Mer tries to stop a metahuman with Super-Strength and Super-Scream powers by wrapping herself around his head. Unfortunately, his inhaling abilities are a bit stronger than expected. Polly states afterwards that it's the first time she's felt what lungs feel like.
- Red Robin: Sac has his spiders crawl inside of one of Ra's al Ghul's trusted workers (trusted in the sense that Ra's had the man's family hostage at gunpoint) in order to force him to divulge information about Ra's' location. When he's done with him Sac has his spiders and the thousands of young in the eggs they'd laid in the man kill him by eating and clawing their way out of him.
- Titans: Beast World: Both the Necrostar spores and the Garro spores enter peoples mouths to control them, rather than the Face Hugger of most Starros.
- A meme that arose in the months leading up to Avengers: Endgame suggested that Ant-Man could defeat Thanos by shrinking down to insect size, crawling up Thanos's butt, and expanding to human or even giant size.
- Dungeon Keeper Ami: In "Assault on Wemos":
One of the spectres supporting the unfortunate vampiric Keeper forced its way into his gaping mouth, slid down his throat, and wrapped around his strained vocal chords. His screams died down as his neck bulged and swelled to grotesque proportions, allowing Zarekos to address his slaves without having to shout.
- Flashpoint 2: Advent Solaris gives us a mature take on "Changelings", which are shown to utilize this trope in a most horrific manner. Their queen lays her eggs inside the corpses of their victims.
- Shattered Skies: The Morning Lights: Slime Girl Jamanen from Sailor Moon appears with a vastly upgraded power set. In a Shout-Out to the infamous Inque scene from Batman Beyond below, she forces herself down Cure Fortune's throat and floods her body... but this doesn't kill her. The process assimilates Fortune's body into a "drone" under Jamanen's control, after which she forces her new servant to beat Cure Black to a pulp while she's helpless to do anything but watch.
- An example heavily overlapping with Eating the Enemy can be seen in chapter 31 of Voyages of the Wild Sea Horse. Nabiki Tendo attempts to defeat her assailant, Nosferatu, by draining her blood. Nosferatu, being a sapient bacteria that can assume human form, reverts to its "true" form, a Blob Monster, and forces its way into Nabiki's stomach, hoping to infect her from the inside out. And then it discovers that, due to her ability to manipulate her own blood, it can't. It then starts desperately trying to rip its way out of her distended stomach, only to end up as a cloud of greasy green ashes that Nabiki burps up when she's done digesting.
- The Little Mermaid (1989): The giant hands Ursula summons go down Ariel's throat to claim her voice.
- Played for laughs in Army of Darkness when one of Ash's miniature clones dives into his mouth. He retaliates by drinking boiling hot water.
- The monster in Baby Blood enters a woman through her vaginal canal.
- Bill & Ted's Bogus Journey: Played for Laughs when Bill and Ted's ghosts try possessing two men. They squeeze in through the ears.
"I totally possessed my dad!"
- Black Wake: The Specimen (played by Kelly Rae LeGault) gives a man a kiss, allowing a parasite inside her to enter his body through his mouth.
- Camel Spiders: A camel spider gets inside of Schwalb's body by climbing into his mouth before the body bag is zipped up.
- Used with a snake in Collateral Damage by the Big Bad to execute a spy.
- Don't Listen: Whenever someone gets possessed by the witch's ghost, a fly enters that person's ear.
- The fly that enters the nose of the main character in Drag Me to Hell.
- Faust: Love of the Damned: During the ritual to summon the Homunculus, M pulls an albino snake out of his mistress' abdomen before forcing it down the throat of an honest cop that he brainwashed to follow him.
- In Flubber, the titular Flubber shoots into Wilson's mouth, wriggles around inside of him, and then explodes out the rear.
- In Freddy vs. Jason, the bug creature in Freeburg's nightmare forces itself down his throat.
- The Hidden: The alien parasite burrows into and out of mouths several times during the movie. One scene used a prosthetic head to show the process in gory detail; upon seeing that scene on film, the actor whose likeness was on the head was physically ill.
- In The Island (2005), the diagnostic sensors (which look like a cross between ticks and spiders) crawl into the body via the eye socket.
- After he is blown to bits in Jason Goes to Hell: The Final Friday, Jason Voorhees's heart mutates into a small creature which does this to take over bodies.
- During the interrogation scene from The Matrix, Agent Smith and his men put a "bug" into Neo, a horrible creature that enters through his belly button. It is exactly as terrifying as it sounds, especially since they had also fused his mouth shut in response to him demanding his phone call.
- In Michael Jackson's Ghosts, the Maestro (played by Michael Jackson) possesses the Mayor (also played by Jackson) through the mouth.
- Piranha 3DD has a baby piranha swimming into a woman's vagina as she's Skinny Dipping, which she somehow doesn't notice. When she's having sex later, the piranha makes short work of the approaching penis.
- A monster in Poltergeist II: The Other Side disguised itself as a tequila worm to take over the dad. However, the dad overcame this and threw it up.
- In Prince of Darkness, The Antichrist is a green liquid which enters into people via their mouths: the hosts then do the same thing to spread the possession, i.e., vomiting into other people's mouths.
- In Scourge, the titular black silverfish-like parasite enters through the navel.
- Shivers (1975): The lust-spreading parasites enter through a person's throat, with someone who's already been infected kissing another person to spread the parasite. Or in one case, through a woman's vagina while she's taking a bath.
- The slugs in Slither enter their hosts through their mouths.
- In Sniper, Thomas Beckett warns his partner not to urinate as they are wading through a waist-deep river, because small organisms will enter his urethra and dig in with spikes.
- Starship Troopers 2: Hero of the Federation introduces a breed of bugs that enter through the mouth to control humans (it's also a convenient way to save on the special effects).
- Star Trek:
- The Decepticon Doctor (Scapel) in Transformers: Revenge of The Fallen reads Sam's brain by sending a small robot up his nose.
- There's a story by Tanith Lee about a demon that takes possession of humans via their orifices, so to try and prevent being possessed one guy blocks all of his orifices, but forgets his urethra. Ow.
- Yeerks take over human beings by way of infestation through the ear canal.
- In The Ellimist Chronicles, Father is a giant sentient sponge (well, sort of) that sticks tendrils into the body to keep its victims alive (or in the case of the dead, keep them from decaying as long as they remain attached) and giving it access to their minds.
- In BIONICLE: Island of Doom, Zaktan "lectures" one of his men, Avak, by dispersing his body into the microscopic insects it's made up of and swarming them into Avak's mouth and eyes.
- Deathlands: In the first book, Krysty Wroth is stripped naked and strung up by her wrists. The baddie then takes a flesh-devouring mutant beetle and shoves it inside her vagina. Rather than see the young woman get eaten alive from the inside, protagonist Ryan Cawdor complies and the beetle is forcibly removed from Krysty.
- Deeplight: The Gathergeist defeated the Swallower by shoving its tentacles into the Swallower's mouth, breaking its jaw, and eating it from the inside.
- The Fallen: Leviathan has people having their bodies taken over by making the creatures enter through their mouths.
- The babelfish of The Hitchhiker's Guide to the Galaxy enters the ear (but just stays in the ear canal), although it's more helpful than other creatures of this trope.
- Ignatius of Horns can exert control over snakes. He uses this to trick a large snake into slithering into the open mouth of an injured villain, resulting in his death.
- The Alien Abduction victims interviewed in Budd Hopkins' Intruders retell of ear probing and possible tracking device installation.
- Just After Sunset: The titular cat from "The Cat from Hell" (adapted into the anthology Tales from the Darkside: The Movie) leaps into the mouth of a hitman hired to kill him, causing the hitman to choke to death before the cat goes all the way down his throat (we read/see just the tail wagging out of the mouth before it disappears into the victim). This really goes with Rule of Scary in the movie, in which the cat is obviously way too big to do this (although vaguely hinted to be a spirit of vengeance).
- In Manifold: Space, the hero Malenfant is integrated with an android/computer system. Tendril-probes infiltrate him... essentially everywhere, and there is no attempt at anesthesia. He is doomed to live for billions of years in this state unless he fails in the task for which he was converted, in which case a stellar event will occur that will kill every living thing in the galaxy except for archaeobacteria and slime moulds.
- Miss Ellicott's School for the Magically Minded: At one point in the story, Japheth, Chantel's Familiar, entered her head through her ear, and stayed in her body for a large part of the story.
- In the short story "Motherhood Redeems Women" by D. Douglas Graham, an aborted fetus decides to return to the womb by the same door he came out. Squick ensues.
- In the Star Trek: Deep Space Nine novel The Siege, an evil shapeshifter kills a Cardassian by ramming himself down the victim's mouth, then expanding inside. In a later novel, Odo threatens to do this to a Cardassian officer should he dare to disturb Odo's regeneration.
- Star Wars Legends:
- Spore, in Galaxy of Fear, combines this with evacuations. Its hosts shoot vinelike tentacles out of their mouths and eyes; these sink into the skins of new victims and they are converted into new hosts within seconds. It doesn't actually leave its current hosts - its unwillingness to ever let go of anyone it's claimed is marked.
- In Luke Skywalker and the Shadows of Mindor, meltmassif/the Melters enter as spines thinner than needles through people's pores. When they're purged, they ooze out of pores and eyes and mouths as oily liquid.
- The biotech of the villainous Yuuzhan Vong in New Jedi Order often does this. Numerous creatures fit the trope more exactly by slithering into ears or eye sockets, or down the mouth.
- One Real Life example is in The Amazing Race when one of the guys wakes up partly covered by leeches, one of which somehow crawled into his urethra.
- In BrainDead (2016), the alien insects who are taking over people's bodies get in by crawling through someone's ear while they're asleep.
- Doctor Who: In the TV Movie, the Master, in the form of a slug-like creature, crawls into the mouth of a sleeping paramedic to take control of his body.
- Legends of Tomorrow: In "The Getaway", a roach belonging to the Egyptian Goddess of Truth enters the mouth of anyone telling a lie to feed, forcing them to tell the truth. Sara tries to prevent this by covering her mouth, but the bug just goes through her nostril instead. Thankfully, Constantine's magic can pull it out.
- An episode of Lexx has space carrots that take over people's bodies by ramming themselves up their anuses.
- In series 4, episode 4 of Misfits, Rudy sleeps in a slug-infested room in the community center, and one of the slugs crawls up his anus. He attempts to remove it by inserting some salt.
- My Hero (2000): Piers voluntarily gets taken over by an alien that enters through his urethra. It's not shown; the scene cuts to the door of the room he's in and we hear an agonized scream. Then we cut back to the room where Piers is bent over in agony, clutching his abdomen and saying to the alien, "Did you have to go in that way?", to which the alien apologizes.
- The Night Gallery episode "The Caterpillar" has a man hiring someone to do away with a rival by planting an earwig in his ear at night, where it will crawl into his head, constantly eating (see "Real Life" below). In a karmic slip-up, he gets it planted in himself. In a million-to-one fluke, he survives weeks of agony when it crawls out his other ear. With the boldness of one who's been through Hell he owns up to his deed and claims he'd do it again... then he finds out that the earwig was an egg-laying female.
- The Outer Limits (1995): The prehistoric worm parasites in the episode "From Within" enter (and later exit as they died) through nostrils, mouths and ears. One girl actually has a worm go in her right ear (complete with blood) and at the end of the episode have it come out her left ear without leaving her with any ill effects (other than a great deal of pain).
- In the River Monsters episode "Amazon Flesheaters", Jeremy Wade interviews a man who has had an unpleasant encounter with a candiru and shows video of the removal surgery.
- The creature that inhabits Helen Magnus of Sanctuary has a parasite exit through her ear canal after she dies. Based on the dialogue, it got in through her pores.
- Sex Sent Me to the E.R. has another allegedly real life instance: a man was meditating in a forest, in the nude, hoping it would improve his sex life (to say It Makes Sense in Context would be a stretch). As he communed with nature, a legless lizard approached him, slithered into his lap, and eventually up his urethra. Oddly, not only did he wait several days to go to the ER for help, but he was more concerned about the welfare of the lizard than his own discomfort.
- Sliders has an episode in which Maggie gets taken over by a parasite that gets in through her mouth.
- Stargate SG-1:
- In a bit of a twist, through the mouth is the more pleasant way for a Goa'uld symbiote to enter a human host: Goa'uld normally enter through the neck, not wishing to see the expression of horror on their future host's face as their body is stolen from them. Only the Tok'ra, a breakaway group who only accept voluntary hosts, normally enter through the mouth.
- Non-Tok'ra will enter through the mouth to avoid leaving a visible scar, however — if they have reason to suspect they will be attacked if discovered.
- In Supernatural, demons usually enter their meat suits' mouths as smoke.
- This is how the Nogisune tends to possess or influence people in Teen Wolf. It takes control of its first body by entering its mouth in the form of a fly. Later, while in Stiles's body, it releases many more flies. They enter Isaac through his IV pump, Ethan through his nose, Aiden through his ear, and Derek through an open wound on his back, and act as a Hate Plague for all four of them.
- Hunting for mole lizards in Baja California, the host of Weird Creatures is told a local Urban Legend that these worm-like animals will invade the anus of anyone who defecates over their burrows.
- This is one of the trademarks of The X-Files. The Black Oil a.k.a. Black Cancer a.k.a. Purity is an alien virus that gets into the human body through the eyes and mouth and assumes complete control over it, optionally using it as a host for gestating a baby alien.
- "Ed Sheeran Gets Everywhere" by Mitch Benn at first just talks about Sheeran's ubiquity in the media, before the singer starts popping up in increasingly surreal places, until:
Now there's Ed Sheeren trickling down my back,
And there's Ed Sheeran in my butt crack.
Now there's Ed Sheeran underneath my skin,
And there's Ed Sheeran getting further in.
Now there's Ed Sheeran inside my head,
And there's no me any more, there's just Ed.
- The Alp-Luachra in Irish folklore is a kind of fairy that takes on the form of a newt and crawls down the throat of anyone who falls asleep near a stream to feed off of the food that person has consumed. The only way to get rid of this creature was to eat a large quantity of salted meat and wait near a stream until the creature left the body to take a drink.
- Dungeons & Dragons:
- The 3.5 edition sourcebook Lords of Madness introduces a new (and decidedly creepy) aberration: the Tsochari (singular Tsochar), a mass of tentacles that bores into victims and can either coerce the victim into behaving itself by causing them great pain or kill the victim and wear the body as a disguise.
- Then there are hellwasp swarms that can enter a dead body and animate it... or enter a living body and force it to do what they want...
- Then there's the process of ceremorphosis, which a mind-flayer tadpole is inserted into the ear of a hapless humanoid (usually a captive human, orc or drow), which eventually turns them into a new mind flayer.
- To crown the collection, there's the DC 90 Escape Artist check from the Epic rules. Combined with Enlarge Person...
- Deadlands has Texas Tummy Twisters and Mexican Blood Babies, which begin their lives as microscopic spore-like animals floating in water sources around Texas and Mexico, respectively. Their whole modus operandi is to wait for some poor sucker to drink unboiled water so they can get inside the body and grow. The Tummy Twister becomes a repulsive, vaguely octopus-like mass of fangs, eyes and tentacles that forces its host to perform evil acts on pain of torture. The Blood Baby develops into a little monster that resemble a deformed human infant before ripping its way out to begin its life of murder and mayhem.
- Daemites from BloodRayne force themselves into the victim's mouth, then take control over the body.
- In Bugsnax, it's revealed that the adorable eponymous creatures are actually parasites that assimilate anything that eats them into the living island they're a part of. As the climax shows, they're willing to resort to Force Feeding themselves to their hosts. Under certain circumstances, it's entirely possible for almost every character to die this way.
- The Mysterious Shadows in Deadly Premonition sometimes do this. Word of God says this is part of an attempt to return to life.
- In Devil May Cry 4, Nero can do this to Bael after stunning him and using Buster directly in front of him. Cue Nero hopping into the demon frog's mouth and slashing him up from the inside before bursting out of his back. Ironic, considering that Bael was repeatedly trying to eat Nero before and during their battle.
- The Bonethieves in Eternal Darkness are spindly, mantis-armed ape-like horrors that can bore their way into a living victim's body and then control it like a puppet. Due to the game's graphical limitations, we're not shown how they do this, but it's heavily implied they force their way down the throat through the mouth, so as to avoid leaving any visible evidence of their presence. This leads to one of the player characters going mad from paranoia and slaughtering all of his servants, since he can't identify which, if any of them, may still be infested by Bonethieves. In-game, you can encounter Bonethieves controlling human side-characters, and the quickest way to kill them is to cut off the host's head, which forces the Bonethief into the open.
- The alien species in Freelancer entered a host through the mouth and effectively take complete control of the body, including the host's memories and personality traits, or at least enough so that nobody realizes that the person they're talking to isn't really the Chancellor anymore...
- Samus can pull this on the final boss of Metroid II: Return of Samus. If you stun it with its mouth open, you can roll down its throat and into its stomach as the morph ball. It doesn't want to spit you back out until you drop a few bombs and inflict massive damage.
- You can also do this in Metroid Prime as a Call-Forward and in Metroid: Other M when you face the Metroid Queen again.
- In a case of Developer's Foresight, it's possible to inflict this on Kraid in Metroid Dread if you obtain the Morph Ball Bombs before you're officially intended to. Observe.
- Mortal Kombat II: One of Shang Tsung's fatalities is forcing himself into his opponent's body, causing them to inflate to ridiculous proportions followed by the victim exploding into a massive shower of blood and bones.
- In one of the dungeons in Pokémon Mystery Dungeon: Explorers of Time/Darkness/Sky, Grovyle is attacked by a Spiritomb, which took control of his body by entering through his nose.
- Resident Evil:
- G-Virus monsters of Resident Evil 2 reproduce by implanting their spawn into a host through the mouth. If the victim is compatible with the monster (related by blood), the victim will mutate into a new one, otherwise the offspring explodes from the chest and mutates into a different monster.
- Several of Las Plaguas were inserted at adult size into the mouth of the victims in Resident Evil 5 for quicker control of the hosts.
- The Death Slug from The Visitor does this in its larva/parasite form, allowing itself to be eaten or taking the back door in order to absorb and messily kill its host.
- The Winter Windster from Wario World flies into Wario's mouth if he looks at him while his eyes are red.
- In Commander Kitty, Commander Kitty ends up with one of his crew rammed up his nose after a transporter accident.
- The slaver wasps in Girl Genius enter the body to enthrall their victims through the mouth.
- In God's World, Arby dives into the Creator's mouth in order to feed him sleeping potions.
- The... uh... nurses(?) in Oglaf use a "polyp of cleansing" to cure the unfortunate Ivan of poison. The phrase "open your food tract, mammal" is employed, followed by a very unpleasant-looking panel. Of course, given which webcomic this is, perhaps we should be glad it was his mouth.
- Yeon from Tower of God falls victim to a Puppeteer Parasite that invades her gastro-intestinal tract. The fact that it was as big as her and disguised as a Monster Clown makes it just as squicky as the fact that the way how it entered her mouth on the bed was shot made it reminiscent of something else entirely.
- In the "Danger Music" episode of Epic NPC Man, the mouse that goes Killer Rabbit on Ben can be seen to leave his neck and crawl into his mouth after he collapses.
- In the animated short "The Pier", a strange creature stalks a bird-man as he fishes for a meal. The creature regurgitates one of its fish-like young into the water, and the child is "caught" by the bird-man who promptly swallows it whole. The baby then starts nibbling on the bird-man's stomach lining, causing him to collapse in agony. The creature grabs the bird-man and forces even more of its young into his throat. The short ends with the children gleefully munching away. Moral of the story? Always chew your food.
- SCP Foundation: SCP-695 ("Eels"). SCP-695's life cycle starts when its juvenile form enters a human male through his mouth, nose, anus, and urethra.
- Whateley Universe: For several (real-world) years, there was a running gag about a Noodle Incident involving Generator, which everyone referred to as... The Noodle Incident. However, when they finally gave Lancer's full (and-spoilerific) Superhero Origin story, author Phoenix Spiritus broke with tradition by describing what actually happened. It involves Jinn demonstrating that even a Flying Brick has trouble breathing when their lungs are filled with animated spaghetti.
- The Ant Man vs. the Atom fight in DEATH BATTLE! ends with Ant Man sneaking several ants into the Atom's body by making them small enough to slip between his cells, then enlarging them inside of the Atom's body so they physically tear their way out.
- In the Adventure Time episode "Jake vs. Me-Mow", Me-Mow climbs into Jake's mouth with a syringe of poison.
- Carrie from The Amazing World of Gumball can possess someone by flying into their mouth and down their throat.
- Played for Laughs a few times in Avatar: The Last Airbender:
- Happens to Sokka when Momo grabs a spider out of his mouth to eat it.
- Momo is missing, and Sokka thinks Appa ate him, so he crawls in Appa's mouth to see. Appa just spits him out.
- In one episode of Batman Beyond, an amorphous woman named Inque tries to suffocate Terry by forcing herself down his throat, which is followed by a scene in which Terry graphically vomits her back up. Unfortunately, this doesn't stop her.
- Code Lyoko:
- XANA's specters generally possess people by entering through the mouth or the ears.
- In the episode "Franz Hopper", instead of possessing one specter tries to clog Jérémie's airways by entering his mouth and nose.
- The Legend of Vox Machina: Scanlan suggests this as a method for he and Vax'ildan to attempt to kill the dragon Umbrasyl from the inside, Vax assumes Scanlan is suggesting they get Umbrasyl to eat them whole and shoots down the idea by pointing out the dragons acid breath. Turns out Scanlan wasn't suggesting taking the front entrance.... queue them both held in one of Scalan's magically projected Giant Hands of Doom as it also extends two of its fingers and zooms towards Umbrasyl's anus.
- Legion of Super Heroes (2006) has Timber Wolf's father infecting him with nanites that enter through his ear while he sleeps.
- Looney Tunes:
- Done in Sylvester's first short "Life with Feathers", in which a henpecked male bird wants to commit suicide, so decides to feed himself to the cat. Of course, Sylvester is suspicious about why the bird would want to do this, so he spends the entire cartoon running away, with the aforementioned bird chasing him and pleading to be eaten. Found here.
- This premise is later used in Cheese Chasers as mice Hubie and Bertie, going off cheese after binging on it, decide there's nothing to live for, and haunt Claude Cat trying to be eaten. Found here.
- In "Beanstalk Bunny", Bugs Bunny and Daffy Duck try to get away from the giant (Elmer Fudd) by crawling into his head, through opposite ears. Elmer isn't hurt (indeed, his head seems quite empty), but gets angry and "smokes" them out by lighting a cigarette.
- In The Unexpected Pest, a mouse that Sylvester uses to make himself appear to be of use to his owners tires of being used and realises that Sylvester needs him to stay alive, so he begins intentionally endangering himself. One of the first ways he does so is to hop into Sylvester's mouth and try to pull it shut.
- In one episode of The Simpsons, Groundskeeper Willie fills the auditorium with rats in revenge for being humiliated. Bart warns Milhouse not to open his mouth; of course, Milhouse starts to say "What?", at which point half a dozen rats leap in.
- Mr. Slave from South Park enjoys forcing small animals to crawl up his ass.
- Star Wars: The Clone Wars:
- The Geonosian Brain Worms enter the victims through the nose and take control of the body. Obi-Wan is more interested in guessing whether it goes in the ear or the nose than worrying about the fact that one of his closest allies is about to be mind-controlled, and he's next.
- A subversion occurs in Season 4 when Obi-Wan voluntarily swallows a "vocal emulator", a spider-like device that changes his voice, in order to perfect his disguise as Bounty Hunter Rako Hardeen.
- Sym-Bionic Titan takes this to a disturbing extreme. Xishi, a squid-like monster about the size of an average human, climbs all the way down her victim's throat and forces them to speak the truth. What's really creepy about it is that Xishi's face is visible from inside the victim's throat.
- In an episode of The Venture Bros., The Monarch threatens to dunk the Venture family in a river teeming with candirus. Bizarrely, Dr. Venture claims that the candiru are a myth (when it's just the part about them crawling into people that's made up).
- The candiru is popular claimed to do this by entering a victim's penis and lodging itself in there. However, such claims about its hunting methods rest on very little evidence, as there has been precisely one documented case of a human attack, in 1997 (which has been disputed). In particular, it is not chemically sensitive to either ammonia (excreted by fish) or urea (by humans) and actually hunts by sight, attacking the gills of its prey. Furthermore, its body shape and hydrodynamics means that it's really not possible for it to force its way into a human urethra. Injuries previously thought to have been caused by candiru infestation and removal are now believed to actually have been caused by piranha biting the genitals of swimmers.
- There's also an urban legend about earwigs crawling into your ears (hence the name), although they don't actually do that.
- Earwigs, as well as spiders and other creepy crawlies, actually do prefer small, tube-like spaces, and will occasionally find their way into someone's ear canal. They'll usually just leave as soon as they discover it's coated with slippery and unpalatable earwax. Supposedly this is why your ears and nose are so susceptible to itching.
- A similar urban legend persists about the average person swallowing seven spiders per year in their sleep, due to the offending arachnid crawling in the nose or mouth and not being able to climb back out. Spiders aren't prone to crawling into damp, breathing caves, so while occasionally this may happen, it's much rarer than the legend portrays. note
- Some Argentinian torture methods during the Dirty War involved a bunch of naked people in a small room, in fetal position, forming a circle. Then, their torturers dropped a starving rat inside the circle the people were making. The rat would try to escape by entering someone's ass, literally.
- There are tales of this sort of torture from many different situations supposedly brutal in their methods. For instance, they say the Imperial Chinese did this from time to time, except that there was only one person and the rat was in a hot cauldron strapped to the victim's ass.
- This is how most scavengers consume carrion, as it requires the least amount of effort to get to the soft fleshy bits.
- Ants, such as army ants, will often attack a larger creature's soft spots in order to bring them down or drive them off. People being attacked by army ants can expect — in addition to painful bites and blisters — to get ants in their mouth, nose, eyes and ears. There have been a few cases where ants have killed infants and small children by invading their mouths and noses and more or less causing them to drown in biting, stinging ants.
- Some species of parasitic worms crawl into people's anuses.
- The pearlfish, a small eel-like creature inhabiting barren underwater sand flats near coral reefs, finds shelter in the hind ends of sea cucumbers. As sea cucumbers breathe through the lining of their anal orifice, the echinoderms can't close them off long enough to stop the pearlfish from slipping into the only available hiding place which their habitat affords.
- On a similar note, clownfish threatened by predators will sometimes retreat into the single orifice of the anemone they use as a home base. As anemones' digestive secretions are quite slow-acting, a brief sojourn in the host anemone's stomach does less harm than facing the predator might.
- Benign example: some pet rats love sticking their heads into their owners' mouths, the better to sniff at the teeth and determine what the human has been eating lately. Rat lovers have even coined a term for this bizarre habit: "rodentistry".
- Several stories have come out of China regarding people having live eels inserted rectally with terrible results. One man died after several friends inserted an eel into his rectum after he passed out following a night of drinking. Another man nearly died after he WILLINGLY put one up there to relieve his constipation.