Rodents of Unusual Size

"Buttercup: What about the R.O.U.S.'s?

Westley: Rodents of Unusual Size? I don't think they exist.

ROUS: RAGH! (attacks Westley)"

- The Princess Bride

Are they so named because they are unusually small, you ask? Heh, heh, heh...

Rats, as you know, are probably the most formidable and tenacious mammals in existence, being blessed with swift feet, durable incisors, impressive cunning and intelligence, numbers, and an all-consuming sense of self-preservation. The only thing they lack, it seems, is physical size and power. Then, given that final boon, they would surely transform from shadow-scurrying scavengers to feared, flesh-rending predators that would have leather-clad barbarians knocking their knees together.

Incidentally, if you don't find the regular-sized rats particularly worrisome already, then we hasten to point out that they are also world-class swimmers and can hold their breath more than long enough to reach the other end of the pipe leading to your toilet. (Thankfully, giant rats can rarely fit through the plumbing.)

Should you encounter these furry freaks, your best defense is to have a Mega Neko by your side. Subtrope of Animals Not to Scale.

Anime

 * Galaxy Angel had this alien hamster thing which they found in the ruins of a once great city.
 * Yu-Gi-Oh has a monster outright called "Giant Rat". Then there are Nimble Momonga, which is just a very large flying squirrel, and a bunch of other more pathetic low-level monsters.

Comic Books

 * Neil Gaiman's gag biography in Sandman: The Season of Mists denies that he was found outside a London sewer unable to say anything more than "Powerful big rats, gentlemen". And then goes on to deny that he had a vestigial tail, played a part in the obviously fictional negotiations between Londons Above and Below, or that there were any tooth marks on the bones.
 * In the Judge Dredd universe they have these. After examining the meat from one they decide to farm them in place of the regular rats they used to farm.
 * Beasts of Burden has a Rat king leading the sewer rats, and his general is a rat larger than the two cats who fight him.
 * There's a Donald Duck comic where Don and his cousin Fethry team up to fight giant rat ghosts. Unusually big rodents shouldn't be a foreign concept to Donald, considering whom he used to co-star with early on his animated career...
 * The Spider Man villain Vermin is a humanoid rat.
 * Prince Raffendorf, from Larry Elmore's Snarfquest comic strip, was a human prince before being turned into a giant humanoid rat by an evil wizard.
 * In Bone, the Giant Rat Creatures, despite that they are drawn without snouts and that they cut off their rat tails as a cultural ritual.
 * One supporting character from The Elementals was a wererat who had a crush on Fathom.

Commercials

 * Several Kia car commercials feature giant hamsters, sometimes complete with giant hamster wheels.
 * In an ad for Doritos, a man puts a piece of an extra-cheesy dorito on a mousetrap, then sits down to eat some more. A giant mouse (well, a man in a mouse suit) bursts out of the wall and tackles him, presumably not being satisfied with the tiny tip of one chip.
 * Orkin's series of Giant Creepy Crawly extermination-service ads now includes one in which a family comes home from a trip to find scruffy human-sized rats hanging out in their living room.
 * There's a commercial for extra-durable work pants which demonstrates their toughness with a giant cartoon beaver, which loses its teeth trying to bite through a pair.

Film

 * Named after the R.O.U.S. from The Princess Bride.
 * The movie adaptation of H. G. Wells' The Food of the Gods features giant rats besieging some people in a cabin. Or rather, it features normal rats romping around a miniature set, and a few prop rat-heads that make "The Talons of Weng-Chiang" look like Aliens by comparison.
 * The film Altered Species has a giant lab rat released by protesters who thanks them by trying to eat them all.
 * In one of the Eddie Murphy The Nutty Professor movies, the Professor accidentally creates a giant hamster.
 * The Cantina Scene in A New Hope features one, and the Star Wars Expanded Universe comes complete with a wide variety of mostly large rodents, sentient and non.
 * And later in A New Hope, Luke describes "womp rats" as being "not much bigger than two meters."
 * The anthology-film Nightmares had a segment in which a rat the size of an SUV terrorized a suburban family.
 * Scrat from Ice Age is a squirrel with Canine Teeth Of Unusual Size, and is obsessed with Acorns Of Even More Unusual Size. Does that count?
 * One appears in the 60s B sci-fi/horror flick Journey to The Seventh Planet. It has no hair, and one eye.
 * Braindead (known in the US as Dead Alive) a 1992 "zomedy" by Peter Jackson features the Sumatran Rat-Monkey of Holmsian fame as the carrier of a zombie virus. Peter Jackson later referenced this in his 2005 remake of "King Kong" by having a crate carrying a Sumatran Rat-Monkey located in the cargo hold of the S.S. Venture.
 * Of Unknown Origin is a surprisingly good movie about a New Yorker who's terrorized by one of these. It's not a mutant. It's not an alien or magical. It's just a big, mean, nasty, and EXTREMELY determined Rattus norvegicus, which figures his apartment is its territory.
 * Rodentz features these creatures as its antagonists, and the film is pretty much just as bad as the name would imply.
 * In the remake of Willard, the role of Ben was played by a Gambian pouched rat, making him far bigger than the rest of Willard's colony.
 * Let us not forget Rats: Night of Terror set in a post-apocalyptic future where the rescuing men in the radiation suits take off their gas masks to reveal that...well I think you know that they ain't gonna be human!
 * The bizarre movie Black Moon featured a truly massive, cat-sized rat (probably an African Pouched Rat) that could talk.
 * Italian movie Quella Villa in Fondo al Parco (aka The Ratman) has a genetically engineered rat-human hybrid wreaking havoc.
 * The formerly human rat monster in Bottom Feeder.
 * Mulberry Street has a virus break out in Manhattan, one that causes people to mutate into homicidial rat creatures.
 * The title dollhouse in Amityville Dollhouse transforms a regular mouse into a giant one. It dies when the house is tipped over.
 * The Killer Shrews features giant shrews. (Well, giant for shrews, at least. Theyr'e played by German-shepherd-sized dogs in cheap prosthetics.)

Literature

 * 1984 by George Orwell features enormous rats, apparently capable of chewing straight through a man's head. The Party uses them as a torture device.
 * The Stephen King short story Graveyard Shift has a lot of rats of usual size...(appears in the collection Night Shift).
 * The James Herbert trilogy of novels: The Rats, Lair and Domain.
 * Reepicheep (and the other Talking Mice) from the Narnia series, who is described to be two feet tall.
 * And he knows no fear.
 * The squirrels too. For some reason, all the Talking Animals in Narnia that would be smallest in our world are slightly larger there, while the biggest ones (like elephants) are slightly smaller. This is Lampshaded in The Magician's Nephew.
 * Given that even Peter could enter their home with ease, Mr. and Mrs. Beaver must've been quite a bit bigger than normal as well.
 * The Goosebumps book Monster Blood II had a 10-foot tall hamster in it.
 * The speculative pop-biology book After Man a Zoology of The Future posits a world 50 million years hence where carnivores have gone extinct and rodents have evolved to fill the niches left by felines, canines, bears, weasels, wolverines, and so on.
 * Doctor Watson makes a passing reference to the story of the giant rat of Sumatra, for which the world is not yet prepared.
 * And Fred Saberhagen picked up that dropped thread in The Holmes/Dracula File, which reveals why the world was not prepared.
 * In the Doctor Who/Holmes crossover All-Consuming Fire, it's an alien being.
 * And in Rick Boyer's The Giant Rat of Sumatra, it's a.
 * The last verse of Genesis's All in a Mouse's Night has a cat getting beaten up with one blow by a giant mouse.
 * The rats from The Nutcracker. Although, technically they were no bigger than the Nutcracker...
 * The Underland Chronicles has these as main characters- not to mention the giant insect and bats....
 * Ratmen (and a genius ratgirl) play a part in Glen Cook's Garrett P.I. series. It seems the wizards of a few generations back had quite a fad for the creation of new sentient lifeforms, and they shared real-world scientists' preference for using rats as research subjects.
 * Like other mammals, rodents were well-represented in the Spellsinger novels, although rats and mice were treated like second-class citizens, forced to wash floors and so on.
 * It seems to be a common subversion that if rats aren't the monsters or the bad guys, they're the Butt Monkey race.
 * The rats in Mrs. Frisby and the Rats of NIMH were Rodents Of Unusual Smarts.
 * Brutus, while certainly not giant, was described as being rather large as rats go.
 * The only non-mutant human creatures seen in the future in Mindwarp are giant rodents the size of a capybara. It is hinted they are descended from rats.
 * The children's novels The Castle in the Attic and The Battle for the Castle, by Elizabeth Winthrop, are about a kid with a magical miniature castle. Through use of a magic token, he can become small enough to enter the castle--and the entire medieval world beyond it. Battle features a battle with giant rats, which makes sense if you think about it, since the rats in the attic don't have magic tokens...
 * Lampshaded in the Russian play "The General Inspector" by Gogol. One character dreams of two "Rodents of Unusual Size" the night before becoming a letter that said inspector is secretly coming to his town - and since he is an Obstructive Bureaucrat, it's a very bad thing indeed.
 * Redwall: In The Long Patrol, Big Bad Damug Warfang is a Greatrat, described as twice the size of a normal rat.
 * While the titular rodents of Paul Zindel's Rats are generally of normal size, the book also features the Rat King (no, not that one), which is described as being even bigger than a capybara.
 * The race of Rumbles in The Borribles are described as rat-like, and are the size of human children.
 * In the ~S. M. Stirling~ book, In the Courts of the Crimson Kings, when the protagonist rescued from a prison, his Martian rescuer warns him that the tunnels under Olympus Mons are inhabited by all manner of unpleasant creatures including rodents of unusual size. They turn out to be thousands of tiny rodents that swarm like army ants.
 * Parrish Plessis has canrats, rat-dog hybrids that are both vicious and intelligent. One of them, the Big One, is the size of a doberman.
 * The H.G. Wells' novel The Food of the Gods features giant rats, about the size of wolves, as part of the mutated ecology that the titular food's unleashed. Unfortunately for humans, the rats also have the carnivorous temperament of wolves and quickly become the dominant pack hunters in the hot zones.
 * The Changelings from The Amazing Maurice And His Educated Rodents tend to be larger than keekees (normal rats), presumably because their intelligence lets them keep themselves better-fed and healthier. Some of the normal rats bred for the fighting-pit by the ratcatchers are also larger than average.
 * The Lemming-Men of Yull from Toby Frost's Space Captain Smith books have armed and industrialized themselves, but still retain their love of jumping off cliffs.
 * The Doormouse is a once-human businessman in the Nightside, who had himself changed into a giant bipedal mouse because he likes being cute and fuzzy. Not a dormouse; his name came about because he's in the business of renting out use of his Cool Gate collection.
 * Alan Dean Foster pulled the same pun in his Spellsinger series, although the doormouse (majordomo in a brothel) was in fact a dormouse. (Spellsinger rodents are much larger than their Earth equivalents, even more so than in Narnia.)
 * All Quiet On the Western Front briefly mentions "corpse" rats, which are basically rats that have gotten huge and fat by eating the corpses of dead soldiers. When the men aren't making war on the enemy they are making war on the rats.
 * Angelina Ballerina
 * Three Skeleton Key
 * The average rat in Domina is about the size of a small dog. That's what happens when you let mad scientists play with a Bio Augmentation device.
 * The Rh/attes are an aptly-named alien race from Chess With A Dragon.

Live Action TV

 * Doctor Who, "The Talons of Weng-Chiang" (considered a Special Effect Failure in actual execution though)
 * The New Avengers episode "Gnaws".
 * Red Dwarf has it in "Back in the Red"- Red Dwarf has been built far too large and is returning to normal size. Starbug encounter a huge rat and ends flying into its backside, propelling it along.
 * The theoretical Shagrat, from The Future Is Wild.
 * The poggle, from 45 million years later in the same program, was a Rodent Of Unusual Staying-power, having survived to be the last mammal on Earth. Not that this did it much good...
 * The widderen in Merlin. Naked Mole Rats Of Unusual Size.
 * On Sabrina the Teenage Witch, we hear the Quizmaster on the phone with an exterminator complaining that the rat in his apartment in the Other Realm is making long-distance calls on his phone and listening to his CDs without putting them back. (Whether he pays rent or not is not the point.) They are apparently unsuccessful since we meet the ROUS in another episode when he introduces himself as the Quizmaster's "roommate."
 * SPG, the pet hamster of Vyvyan on The Young Ones, was usually played by a puppet the size of a guinea pig rather than the size of a real hamster. In one episode, he scarfed down an entire potfull of lentils and swelled up to volleyball size.

Music

 * The Radioactive Hamsters From a Planet Near Mars.
 * Green Day had an album cover where a gigantic Hamster was attacking society.
 * There's a New York punk band named Rats of Unusual Size.
 * The World War One song "The Quartermaster's Store" mentions "rats, rats, as big as bloody cats" (see also Real Life).

Mythology

 * There's a Japanese legend called "The Boy Who Drew Cats", in which a city is plagued by a giant demonic rat. Which is eventually killed by the titular drawings of cats. It's magical, okay?
 * Also from Japan: Tesso (Iron Rat), a former human noble with Jerkass, ungrateful parents who was cursed by a monk. He's a man-rat hybrid that raids the temples and the houses with a horde of smaller rats and devour everything on his path.

Periodicals

 * This is an occasional gag in Garfield; Garfield will be pretending to mouse, or maybe teasing a mouse and the mouse will be larger than normal. Then there's the Training Mouse from the arc where Garfield got locked out and found his way back to where Mama Leoni's used to be.
 * The infamous "Moon Hoax", a series of articles in the 19th century New York Sun, included fanciful accounts of giant civilized beavers living on the moon.
 * In an early issue of What's New? With Phil And Dixie, Phil distracts a giant monster rat by throwing a live cat at it.

Tabletop Games

 * Some people think that the Warhammer universe contains the Skaven, three-foot tall ratmen, using giant rats and rat-ogres, but they are of course mad.
 * Or form Middenland, since you know you have been attacked by a massive army of said three-foot ratmen with lazer cannons
 * Don't be silly, those were just Beastmen. There certainly aren't any giant ra-AAAAGH * slumps to ground with glowing green dagger embedded in ribcage*
 * The underhive in Necromunda (part of the Warhammer 40000 setting) is infested with these. And not just any giant rats - more intelligent, mutated giant rats. Some are spiky, some have two heads, but they all are happy to eat lone humans if they think they can get away with it.
 * Of course, humans are more than happy to return the favor. While the uppermost Hive Dwellers might feast on food exported from agri-worlds, the average Underhiver has a distinctly less pleasant variety of foodstuffs to choose between. The most "normal" foods are fungi and edible slime-molds. "Meat" in the Underhive generally comes from rats... or snakes... or spiders... or, really, anything made of meat that fails to climb out of the pot. The nastier folks are even willing to add their fellow man to the list. To say nothing of such delights as "Wild Snake", a popular booze made from a certain species of giant snake.
 * The Hrud of the same universe, sometimes called "Space Skaven", might also qualify, at least if writers were not trying to Retcon their appearance.
 * "Dire rats" are a common low-level monster in Dungeons and Dragons that often show up in caves and city sewers. They're scavengers who won't hesitate to attack live prey if they think they can get away with it and carry disease more often than not. There are also wererats, humanoids cursed to change into dire rats much like werewolves.
 * You're forgetting rat swarms, skeletal rat swarms, corpse rat swarms (Zombies!!!), spectral swarms (incorporeal undead that typically result from careless fireball-flinging adventurers inflicting large amounts of collateral damage on the local rat population), cranium rat swarms (psychic rats!!!), moonrats (rats that become more or less intelligent depending on the phases of the moon), and the Tamer of Beasts prestige class from the book Masters of the Wild, who is depicted in the artwork as controlling a massive army of rats.
 * And there's the Rylkar from Version 3.5's Monster Manual V. They're basically a nest of giant, evil rats who are connected via a hive mind to their harridan, the huge, disease and corruption spreading, blind matriarch of the nest.
 * The Spelljammer supplement for 2nd edition D&D introduces the infamous Giant Space Hamsters, domesticated and bred by the Gadgeteer Genius Tinker Gnomes of Krynn, and coming in a wide variety of breeds including the "Miniature Giant Space Hamster", which is identical to an ordinary hamster.
 * Previous editions of D&D also included giant beavers, giant porcupines, and -- I kid you not -- giant carnivorous flying squirrels.
 * Rat flail.
 * Rat... MORNING STAR!
 * One highly popular adventure from the early days of Dungeon magazine shrank the PCs down to the size of gaming miniatures, making ordinary rats appear enormous by comparison. Other humanoids, who'd previously fallen victim to the same magic, used rats as steeds.
 * Magic: the Gathering has 'Rat' as a creature type, from the classic Plague Rats that only the four-of-a-card deck construction limit really keeps from growing arbitrarily dangerous to the Kamigawa block's nezumi (rat-people complete with their own warriors, rogues, shamans and ninja).
 * Relentless Rats was designed and printed to allow people to enjoy plague rats without the four-of-rule, explicitly stating that it ignores it. Also is much better.
 * The original art of Giant growth featured a giant rat. Now it's a bear.
 * An enemy from Vampire: The Masquerade is called a Ghoul Rat. It is the size of an Irish Wolfhound.
 * There is also a changing breed in the World of Darkness called the Ratkin, that are sometimes born as humans (that have the ratkin genetics) and contract a disease that, should they overcome it, turns them into wererats. They were given the charge by Gaia to help control the human population by eating their food and spreadin disease.
 * These Ratkin can take a talent to be able to transform into a giant rat that can stand approx. 4 ft. at the shoulders.
 * In Shadowrun, devil rats are Awakened rodents the size of a border collie. They're nasty, vicious, disease-carrying, and (for some reason) bald all over.
 * The New World of Darkness has Beshilu, one of the two iconic races of the bizarre half-spirit Hosts (the other being the Azlu). Like their cousins, they start off looking like normal rats, but quickly gain size and sentience as they eat real rats and lesser Beshilu. They then gradually gain the ability to control human corpses and eventually become humanoid, where they become far more social then other Hosts, froming tribal societies. That wouldn't be so bad-they don't prey on humans all that much-except that they also are driven by instinct to gnaw holes in the barrier between the Spirit World and the human one, which, given where they live (ie, where normal rats live), quickly becomes a haven for disease-spirits, who of course, exist to spread disease. And like other hosts, killing them simply causes a large one to split into a swarm of rats, with one of the component rats containing his soul-which, if left alone, will eventually grow back to full size and power.
 * In the miniatures game Song Of The Splintered Lands (based loosely on Redwall) all of the "evil" talking animals were cannibalistic carnivores -- except the rats. The rats just had a bit of a problem with the Druid's edicts about population control.
 * Mortasheen has a few, including the amoebic; thieving Gravesnitch, the oddly-toothed Gnawful, the cold-loving Abomignash, and the absolutely disturbing Vermoeba (Which is based on the Rat King detailed below)

Video Games

 * Pokémon has quite a few of these, often Com Mons. Examples include Rattata, Pachirisu, and of course, the Pikachu family.
 * Super Smash Bros has very scary implications if it weren't for the fact that the characters are trophies. Imagine, if you will, dropping a life-sized Pikachu on Pop Star or Hocotate. A malicious Pikachu (or however many more) in either of those settings would be a Cthulhuesque horror upon the populations of those worlds, as it fits ALL of the ROUS criteria without the use of Super 'Shrooms.
 * Somewhat justified because they are usually cute, big eyed and not very menacing. Not even those with teeth bared are all that terrifying.
 * Ultima Underworld II features giant rats of various types.
 * Breath of Fire does the small player thing, but with cockroaches.
 * Fallout has rats the size of the vault dweller's foot.
 * For starters. Pig rats are the size of the vault dweller's leg, and mole rats, the vault dweller.
 * Fallout 3 has a robot you can activate in the Old Olney Tunnels that mentions something during its startup sequence about an infestation of rodents of unusual size..
 * Fallout: New Vegas has a direct quote from The Princess Bride (see quote at top) when doing the Debt Collector quest's final part in Broc Flower Cave, which is of course filled with Rodents of Unusual Size.
 * Elder Scrolls III had giant rats, and in an expansion, tamed giant rats that carried extra stuff for your character.
 * The Elder Scrolls IV had a vast array of underground catacombs and Romantic secret passages lit by torchlight. It was damp. There were rats.
 * There's also a woman in one of the cities that keeps pet rats. Her rival hated them, and so put out meat to lure them, which had the effect of attracting mountain lions which came and killed a few of the rats. The lions were surprisingly weak in battle compared to the ones you usually fight in the wild.
 * That's because they were starved.
 * In Skyrim they're called skeevers. They're so big that people lay down bear traps to catch them. One crazy guy underground tried to create an army of them.
 * Twitch, a champion in League of Legends, was a sewer rat who gained sentience and bipedal form from magical runoff. Lonely and a bit maniacal, his goal is to duplicate the phenomenon and create a race of sentient rats to rule over.
 * In the 1990s PC fantasy kingdom sim Majesty, giant rats were generally the first monsters to show up in your kingdom.
 * And rat-men were another common annoyance, though they were at least one of the few enemies your city guard could handle competently.
 * Puzzle Quest: Challenge Of The Warlords has giant rats, scorpions, bats, and wasps. The first two can be captured and ridden, granting the player a different stat bonus and additional spell, depending on which one you choose.
 * Suikoden II had a giant, mutated Sewer Rat for a boss. Which could attack twice per turn, and hit all of your party with each attack for a lot of damage. Goddamn rats.
 * Final Fantasy III had one too. It is unusual, in that it is a normal-sized rat, but your party has to use the Mini condition to reach the Plot Coupon it's guarding. Since the Mini status effect cuts Defense and Attack to 1, you're basically forced to go at it with a party of Squishy Wizards. Best bet is to change your physical fighters into Red Mages for the duration of the dungeon, since you don't have the advanced spells they're locked out of at this point of the game.
 * Tales of Symphonia has a similar situation where the party gets shrunk down in a sewer and meets the same itty bitty mice which they can encounter as GIANT KICKBOXING MICE.
 * Shining Force 2 has rat enemies of both varieties as the above examples. On the first battle on the field, the party encounters Huge Rats. Later in the game, the party gets shrunk down as part of the storyline and faces normal-sized rats. Your stats don't suffer the debilitating effects of Mini like in FFIII, but those normal rats are still hella strong. And led by a super-rat named Willard.
 * Not to mention Slade the rat thief who started the entire mess in the game by stealing the Jewels of Light and Evil. Including him in the fight with Willard causes instant Furry Confusion because Slade is anthropomorphic.
 * In the "Down the Tubes" and "Tube Race" levels of Earthworm Jim, the only way to get through several corridors full of tiny bruisers who will slam you around and throw you back where you came from is to ride a giant, foe-eating hamster ("Whoooooooa Nelliiiiiiiie!").
 * The Magi Nation series mostly features decidedly non-real-looking creatures, but the Always Chaotic Evil Core region does get one very large rat-like creature. It's even named "Rous," in a direct Shout Out to the Trope Namer.
 * Mouser from Super Mario Bros 2 is a gigantic bomb throwing killer mouse boss. Who has probably the most ironic kind of name ever for such a creature (considering the word 'mouser' means 'cat which catches mice').
 * Ever Quest's Ratonga are prime examples of what happens when you give a ROUS opposable thumbs and knives. An entire race of automatically Evil aligned ROUSes with a penchant for being thieves and assassins. Throw in Roekillik, their Minime counterpart race, and it seems someone at Sony rather likes this trope
 * Every roleplaying game Spiderweb Software has ever made, with the exception of the original Geneforge, has giant rats in it. They're usually the very first enemies you fight before you go on any quests.
 * Castle of the Winds has Giant Rat, but it's pitifully weak. No, it's the ants that new characters should watch out for.
 * Adventure Quest has BURPS, which stands for "Big Ugly Rat Pests". They're Exactly What It Says On the Tin. And every other year there's a war fighting nothing BUT those guys. They also qualify as Goddamned Bats because they're a pain in the ass to hit, where as the bigger ones deal quite a bit of damage. At higher levels you'll still be fighting the guys, often in groups.
 * It gets better--one of their variants is actually called the ROUS.
 * Parasite Eve had mutated rodents that tried to kill you. And giant squirrels, too.
 * Rattus giganteus is a common creature in Beyond Good and Evil. While it's not as big as other examples of this trope (nor as its name would suggest), it occurs in such numbers that it's still a hindrance.
 * Project Eden features normal sized rats that transform into giant acid spraying monstrosities
 * Played for laughs at the start of The Bards Tale, where the eponymous Bard goes into the basement of a tavern to kill a rat for the hostess. After some patronising dialogue from the narrator, a giant rat emerges from the darkness, and breathes fire on the Bard, forcing him to retreat back above ground. Turns out it was all just a prank, which the drunken patrons got a good laugh out of.
 * The Duck Tales video game for the NES had that giant rat boss guarding the Green Cheese treasure in The Moon stage.
 * Played with in Baldur's Gate, where Minsc's pet rodent Boo is an unusually small "miniature giant space hamster". "Go for the eyes, Boo!"
 * The Kodama Rats in La-Mulana, which explode.
 * The bonus-content version of the credits from Resorting To Danger includes a clip of Casper the albino squirrel, grown to the size of an elephant, destroying the laboratory by shooting laser beams from his eyes.
 * Mirror's Edge breaks realism to include one, if you fire at a certain sign with a sniper rifle.
 * The second Resident Evil Out Break game features those rats that spread the T-Virus attacking one of HUNK's men after he'd been felled by Birkin. There was also artwork showing muntant rats that didn't make the game.
 * EarthBound features a Sanctuary Guardian called the Plague Rat of Doom.
 * In the Human Noble origin in Dragon Age Origins, you fight a bunch of giant rats who got into the kitchen larder.
 * Dark Cloud 2 fills several levels of its sewer with them.
 * Giant rats were the most basic enemy type in the Gauntlet clone Demon Stalkers.
 * The GBC versions of the Harry Potter games feature giant rats as enemies.
 * The Rat-Men from Titan Quest. You first fight the weak, thin ones in Greece and then meet their larger, strongers cousins in Orient.
 * The Wolf-Rats from Drakensang. Expecially Mother Ratinsky and Great Chief Ratzinger.
 * The Sims Medieval has dire chinchillas.
 * Dark Souls has these. Very predictable and easy to kill but inflict poison.
 * In Battletoads, large humanoid rats are the Dark Queen's primary contingent of Mooks.
 * There's also "Big Bad Blag" which is a giant, fat anthropomorphic rat even larger than the toads themselves.
 * Duke Nukem Forever has regular-sized rats attacking Duke... after he's been hit by the effects of a shrinking device. Duke then quips "Talk about your rodents of unusual size!"

Webcomics

 * Giant mutant rodents are the signature creation of Narbonic's Helen Narbon. Of course, Helen being a young girl at heart, they happen to be giant mutant gerbils.
 * The trope name is evoked in the title of an Eight Bit Theater episode which discusses dire rats... but the resulting rodent isn't one, just an Ax Crazy dwarf disguised to chase for it.
 * The Sturmhalten sewer guides in Girl Genius are actually surprised to learn that sewer rats aren't supposed to be giant and glowing.
 * "60 centimeters. Tops."
 * Lars is understandably worried.
 * Even so, sixty centimeters is pretty sizeable for a rat; especially since, during the approximate time period Girl Genius takes place in (assuming sometime during the 1700s, given a couple hints), the most prevalent variety would be the black rat, as the Norway rat was at that point only getting started driving the black rat to warmer areas. Norway rats are noticeably bigger than black rats, and even for them, sixty centimeters (about two feet) tip-to-tail is pretty big.
 * Not surprisingly, Furry Comic Super Mega Topia has several larger anthropomorphic rodents, including Distraction Damsel (though she's only really big where it counts, Mighty Mighty Hamster, and of course, the World's Largest Hamster.
 * Secretary, the second arc of Nature of Nature's Art, plays with this trope. All of the important characters are rodents in this arc, and some are bigger than others. In the end, though, the only one who plays the trope straight is the advanced class teacher - he makes degus (SV and NT) and chinchillas (SV's teacher) look small, and early in the arc, a mouse called NT "huge".
 * Hamstard, the Bastard Hamster mascot of Erfworld's in-character blog, qualifies by virtue of being incredibly fat. Really, Parson should've gotten the little blob an exercise wheel before being swept off to another dimension...
 * In the Blade of Toshubi we have Toshubi, a human-sized anthropomorphic mouse from a village of human-sized anthropomorphic mice.
 * In Yamara, Tim the paladin is turned into a vampire, but messes up his first attempt to turn into a bat, becoming a giant flying squirrel instead.

Web Original

 * Actually older than Web Original, as it goes back to Usenet, the Internet Oracle has as his arch enemy Woodchucks. The reason is the infamous Woodchuck question he is constantly asked, "How much wood could a woodchuck chuck if a woodchuck could chuck wood?". Some of his enemy woodchucks were rather large. After The Princess Bride came out, they were given the official name of "R.O.U.S.".
 * Squirrels are one of the eight sentient (i.e., humanoid) species in Tasakeru. They're the only rodent species among sentientkind; the others are canines (wolves and foxes), mustelids (badgers, ferrets, raccoons, and skunks), and lepines (rabbits).
 * Monster Slayers features these as one of the enemies.
 * Kizzsprite is a chinchilla, resurrected as a kernelsprite. Of course, much weird plot shit surrounds him. We probably shouldn't get any further than that.

Western Animation
"Rat...robot. Rat...robot. I'm a robot and a rat! Yeah, I like it!"
 * Splinter from Teenage Mutant Ninja Turtles is a pet rat who was mutated into a four foot rat-man.
 * Or, if you refer to the 1987 series, a human mutated into a four foot sewer rat.
 * Mickey Mouse is a three foot tall mouse. Good thing he's not dangerous. Well, usually
 * Robin Williams jokes that his son was traumatized by the actor playing Mickey Mouse at Disneyland.
 * Rattrap, of Transformers: Beast Wars and Beast Machines, transforms into a giant rat, a choice influenced by Transformation Conventions. While not the genuine article, his personality is such that he might as well be, and he certainly seems to think of himself as one.


 * The quote above was said immediately after all the Maximals had a breakthrough of sorts resulting in the merging of their Transformer and animal psyches. Just saying.
 * Gorgonzola from Chowder
 * Also overabundance of giant rats is apparently why Mung keeps poison in the spice cabinet.
 * Furry Confusion anyone?
 * They're actually just as intelligent as gorgonzola is, make of that what you will.
 * Biker Mice From Mars.
 * Bugs Bunny, Lola Bunny, Babs and Buster Bunny (no relation), and Ace and Lexi Bunny, all from Warner Brothers.
 * Actually, these are Lagomorphs of Unusual Size, since Lagamoprha is a separate Order from Rodentia. However, this Taxonomic Term Confusion is not so much You Fail Biology Forever as Science Marches On; lagomorphs were considerd to be rodents until the early 1900s.
 * Slappy Squirrel, her nephew Skippy, and their neighbor Candie Chipmunk, all from Animaniacs, do qualify.
 * Godzilla the Series featured the titular reptile chasing down giant rats in New York City in an episode entitled "Cat and Mouse."
 * Invader Zim had Pee-Pee the hamster. Zim used his newfound knowledge of the human weakness to cute things to make Pee-Pee into a virtually unstoppable monster.
 * ...of course, then he realized he had no way to control said unstoppable monster, leading to an Enemy Mine situation.
 * The Penguins of Madagascar features King Rat, a tall, muscle-bound mutated lab rat who occasionally leaves the sewer to make trouble for the penguins.
 * South Park was attacked by giant carnivorous guinea pigs. The guinea pig community was quite full of Squee over it.
 * The Tick had Speak, his pet capybara (see Real Life, below), much to Arthur's dismay.
 * Chip 'n Dale Rescue Rangers: Hero example: in one episode, the Rescue Rangers (a fly and four rodents) are enlarged to human size.
 * That Family Guy episode about the world being destroyed by Y2K. The Griffins leave Joe to fight a giant mutant rat. His response? "Bring It On!!!
 * An episode of Aladdin featured rat people, who were only slightly shorter than Jasmine and Aladdin.
 * Ratigan from The Great Mouse Detective gets especially scary looking in the climax of the movie.
 * An episode of Jimmy Two-Shoes featured a rat bigger than a horse attacking Beezy.
 * More than one cartoon from Looney Tunes involved Sylvester thinking he's encountered this trope, but it's really a young kangaroo that keeps swapping places with the mouse he's after and smacking him around.
 * And of course Jerry pulled the same trick on Tom, with a baby elephant.
 * In Back At the Barnyard when everyone got a clone, said clones were all mini-sized.. except Pip's, who went the other way.
 * Alvin and The Chipmunks in their animated incarnations. They're chipmunks and are never implied to be anything but chipmunks, but they're generally about four feet tall. The newer CG-animated remake has them at actual chipmunk size.
 * Mr. Ratburn from Arthur.
 * Alcazar's friend Rat Man and his girlfriend, from Futurama.
 * Godzilla the Series Has Godzilla Jr. fight among the Monster of the Week giant mutant rats http://godzilla.wikia.com/wiki/Giant_Rats of various types and even a giant mutant shrew http://godzilla.wikia.com/wiki/The_Shrewster.
 * The Tex Avery classic King Size Canary has a cat trying to make a decent meal out of a puny canary by feeding it fast-growth plant food. It works alarmingly well, and soon the cat, the bird, a mouse, and a bulldog are all taking swigs of the stuff, jockeying for size supremacy. The cartoon ends with the cat and mouse waving goodbye to us, standing on a relative beach ball sized planet Earth.
 * One episode of Cyberchase involved The Hacker using a giant hamster called a hamborg (which for some reason resembled a capybara) as part of his evil plan.
 * In the Wile E Coyote and The Roadrunner cartoon "Chariots of Fur", Wile E. tries to catch the Roadrunner with a giant mousetrap. Instead, he snags a giant mouse, who then turns the tables on him.

Real Life

 * The capybara, the beaver and the porcupine (the three largest living rodents)
 * A "rat king" is the name given to a group of rats whose tails are so mired in muck and filth that they are permanently stuck together. Just as horrifying today as it was back in the sixteenth century.
 * One wonders how long a rat king would survive. Counting "survival" as the amount of time between forming a rat king and the number of component rats which are dead being sufficient to noticeably hamper the surviving ones.
 * We're talking about animals that have been known to gnaw through concrete and that will eat just about anything. I'm not sure individual dead rats would be connected very long.
 * The leading theory of their creation is "cruel guy with time on his hands".
 * Trench rats in World War One were often reported to grow to the size of house cats, because of their constant engorging on the corpses in No Man's Land and the soldiers' food. And when feasting on the corpses, these bloated rats ate out the corpses' eyes first. This site has a little article about the trench rats in WW 1. Imagine sleeping with overgrown, bloated rats the size of a house cat running across your face. Nightmare fuel, no?
 * There is an entire episode of the t.v. show Monster Quest that deals with sightings of cat or even dog-sized rats in major U.S. cities like New York, including a homeless man who reported a 3-foot giant in an abandoned subway tunnel.
 * In New Orleans, Coypu (once farmed for their fur) have established breeding populations along the city's levees and waterways, where they are sometimes mistaken for Rats Of Unusual Size. These semiaquatic mammals are actually from a different family of rodent than rats, and are supposed to be the size of tomcats.
 * If you ever see a "giant killer rat" in a sideshow, it's probably a coypu. (They used to use capybaras, but those are incredibly high-maintenence.)
 * The Gambian giant pouched rat can grow to over 2' long, and is one of the largest rodents to be formally classified as "rats". They've been trained to sniff out land mines in Africa, which kinda subverts this trope's "feared, flesh-rending predator" aspect.
 * The tragically critically-endangered Cloud Rats of the Philippines. As cute as living stuff toys!
 * The Indian Giant Squirrel is aptly named.
 * And according to this article, the largest known rat of unusual size has recently been discovered in a crater in Mt. Bosavi.
 * And it's completely docile, too.
 * Prehistoric rodents could get absolutely gigantic: Neochoerus pinckneyi is a Capybara 40% larger than its modern cousin (200-250lbs); Casteroidies, a beaver the size of a VW Bug (8ft long, 200+ lbs); Phoberomys pattersoni is one of largest of all known rodents, growing to almost 10ft in length with an additional 4ft of tail, weighing up to 1,500lbs; The largest goes to Josephoartigasia monesi which did hit 10ft long, stood 5ft tall at the shoulder and weighed over a ton (it's incisor teeth were a foot in length). A lot of these giant South American rodents are basically even bigger capybara.
 * The rodent taxon is of unusual size, as it contains more than 40% of all mammal species.