"Fur the color of dead grass conceals a hard, scaly exoskeleton protecting this flesh-eater with few known predators. Its head is concealed by a split upper and lower jaw, and it is from between these that it keeps careful watch on prey through well protected sunken eyeholes."
It doesn't look like a duck, walk like a duck, or quack like a duck, but everyone around you insists it's a duck.
Just as Speculative Fiction authors like to Call a Rabbit a "Smeerp", they also like to invent wild new creatures, give them the names of familiar animals, and plunk them down into their settings to run amok. The differences between the smeerps and their real-world counterparts can range from mild — such as "dogs" that have spiked backs and three tails in addition to all their normally canine traits — to extreme, such as bipedal, poison-spitting, frilled reptiles with saddles being referred to as "horses".
When used in non-visual media, the problem is that unless the author is very explicit right up front about the fact that the animal in question is quite different from what the word normally means, the reader may be hundreds of pages in before he runs across something that just doesn't make sense, which can be jarring. It shatters the Suspension of Disbelief when you have to suddenly change your mental image of the hero's faithful dog to include scales and a forked tongue.
A common trope in RPGs, especially when naming monsters.
There is some Truth in Television here—explorers would name newly discovered animals after the ones they were familiar with due to a resemblance in how it looks, sounds, or acts. This is why, for example, you'd need to distinguish between African, American, and Eurasian buffalo—Portuguese explorers in the 1580s called African buffalo "big oxes" in their language; French traders in the 1630s independently applied their own cognate term to the large bovines of North America; and then in the early 18th century Europeans applied the term to the water buffalo of Asia (unlike the previous two times, that was probably a deliberate comparison to another "buffalo", namely the African one, rather than simply "big ox").
And for whatever reason, everyone thought that every animal would have an "alien" equivalent. The closest equivalent to outer space back then was the ocean. Have you noticed how many sea creatures have names like "Sea/Mer + Name of Land Animal", e.g. Sea Lion, Cow, Horse, Slug, and Cucumber? RPGs like to run with this too. Note that quite a few cases are due to translation errors (see Dinosaurs Are Dragons for a specific example of this).
Note that in Real Life, this trope can involve the linguistic debate on prescriptivism vs. descriptivism—if an animal is commonly called something, that is by definition its common name; it's only "wrong" if it doesn't convey what animal is being referred to. Common parlance is not professional taxonomic literature, which has binomial nomenclature to prevent ambiguities.
The inverse of Call a Rabbit a "Smeerp". When already fictional creatures bear little resemblance to their mythological counterparts, it is, depending on the case in question, either Our Monsters Are Different or Call a Pegasus a "Hippogriff". Occasionally might be related to Translation Convention. See also Horse of a Different Color and SpaceX. Not to be confused with In Name Only. Closely related to Non-Indicative Name.
Plue is the source of endless confusion for the protagonist. He's white, has a horn-like nose, eats lollipops, and alters between walking on two legs and four, and has on one occasion been indecisive over his own gender. So far people have accused him of being a dog, an insect, a cat (though the person who guessed this went on to guess a specific breed that was a dog anyway), a water demon, a snowman, or an alien. (Word of God cheerfully insists he's a dog, though.)
Additionally, the group occasionally travel around in a cart pulled by a "horse"... which is purple, bipedal and reptilian in appearance, and constantly shakes its head back and forth rapidly. That horse also has a trunk and makes a weird engine-like sound. Admittedly, Griff is the only one to insist that the thing pulling his cart is a horse. It is lampshaded several times by the other characters.
Plue gets this treatment again when Lucy summons him in Fairy Tail. At least Natsu and Happy doubt her when she insists that she has summoned a dog spirit. They seem to give up on arguing with her almost immediately though. On that note Happy himself, while indeed having cat-like head, is of a solid blue colour, walks on hind legs, speaks, can sprout wings and carry people around, has hatched from an egg... But everybody calls him a cat. In Edolas Arc we learn that the proper name for his species is Exceed, but everybody keeps calling them cats.
Biomega features bizarre technorganic Big Creepy-Crawlies referred to as horses. Then again, the people who ride them seem to have a very loose definition of the word, as this is also what they call the main character's motorcycle.
Though the aliens of Keroro Gunsou do look somewhat amphibious, they are far closer to the standard Little Green Men than frogs. Could be a result of stylized art (look at the humans in the series) rather than them not looking like frogs.
Animals in (on) Nagasarete Airantou may as well be animals in name only. Lampshaded heavily by Ikuto in the beginning but he's since taken it in stride (especially those cotton balls they call "sheep"). Whenever a "real" animal appears it is given such "real" detail that even animals of the same species on Airantou find it horrifying.
In Monsters, Inc., Mikey has an old stuffed animal — it's a cyclopean horned monster (like him) but with six legs. What does he call it? A "teddy bear". They likely have picked up their knowledge of "teddy bears" from the children they scared; small children tend to call any plush a "teddy bear", regardless of whether said plush looks anything like a bear. Even adults do it sometimes — just check eBay.
Also Boo calls the Hulking monster Sully "Kitty!".
Contrary to popular belief, actual Aracuan birds look absolutely nothing like the one seen in The Three Caballeros.
Most of the prehistoric animals from the Ice Age series films are all referred by the names of modern-day animals. For example, Diego the Saber-toothed Cat is still referred as a tiger. On the other hand, Sabre-toothed Tiger is a common name for his species, and their scientific name (Smilodon) doesn't exactly roll off the tongue.
In Despicable Me, Gru introduces the girls to his pet, Kyle; a small, toothy, yet menacing little beast. He uses this trope because he doesn't seem to know what Kyle is.
In Willow, Queen Bavmorda's vaguely canine hunting beasts look more like giant furry/scaly warthogs but are consistently referred to as "dogs". Probably because "hunting pigs" sounded silly and they were using dressed-up Rottweilers anyway.
The non-flying steeds ridden by Na'Vi in Avatar are six-limbed blue nectar-eaters that breathe through opercula on their chests. While technically dubbed "direhorses" by humans, they get called "horses" for short a lot.
Ghostbusters: "OK... so... She's a dog." (Technically, a demon dog, but...)
Despite taking place in a fictional, separate galaxy, the Star Wars films feature objects that are actually named after real-world animals, such as the Millenium Falcon.
The novelization has some fun with this. After agreeing to teach Luke in the Jedi ways, Obi-Wan quotes the saying, "Even a duck must learn to swim." Luke immediately asks what a "duck" is. (Considering that Luke grew up on a desert planet, it makes sense that he wouldn't have encountered ducks.)
The "Velociraptors" in Jurassic Park were larger and had heads of a different shape when compared to actual velociraptors. That is because they were actually based on a related predator, the Deinonychus. This happened because when the novel was written, a scientist had proposed that Deinonychus was a species of Velociraptor (disregarding the fact that it was twice its size and lived 20 million years earlier in a different continent)—and the film went with that even though the scientific community wrote it off before filming took place. And, even taking Deinonychus into account, it'd look more like Velociraptor than the movie animals; in 20 years, the roughly inaccurate view was turned into what looks a fully different animal.
The Dilophosaurus in said movie is also quite distinct from the animal we know; a child-sized cross of frilled lizard and spitting cobra doesn't resemble the bear-sized animal that once roamed Arizona.
The Loch Ness Monster from The Water Horse looks more like a kid-friendly plesiosaur than a horse.
Other than being simply labeled "Bugs" as a Fantastic Slur towards the chitinous alien invaders and their various castes in Starship Troopers, their official label is "Arachnid". This is confusing as it is never shown if they have any sort of relation to Earth's anthropods despite the superficial resemblance.
Subverted with the aliens in District 9. People call them prawns, which sounds weird because they're more insectoid than crustacean, but it's actually in reference to a type of South African cricket which they actually do look a fair bit like.
In The Big Lebowski, the Nihilists invade the Dude's home and threaten him with a ferret, which he mistakenly calls a marmot.
Bringing Up Baby combines this with a bizarrely specific form of Misplaced Wildlife; Katherine Hepburn has bought what she calls a leopard, but is actually a jaguar, from Brazil, where leopards don't live but jaguars do.
Actually mentioned by name in Mike Resnick's short story "Stalking the Unicorn with Gun and Camera", e.g. in the following line: "A word of warning about the smerp: with its long ears and cute fuzzy body, it resembles nothing more than an oversized rabbit—but calling a smerp a rabbit doesn't make it one." This is probably a Shout-Out to James Blish's original "Call a Rabbit a Smeerp".
Happens a time or three in The Telnarian Histories (by the same author as the Gor series). They're along the lines of "He had a dog. Well, not a dog as you know it, but it's the closest equivalent in your ecosystem, so we'll call it a dog. It had the usual seven flippers, but only three of them were orange..." (Note: We made up the flipper part. The descriptions in the books are much more serious.)
Terry Pratchett's first novel, The Carpet People, does this for just about everything but silverfish. Horses have colour-changing multifaceted eyes, among other things.
Gene Wolfe's Book of the New Sun, full stop. Wolfe's use of archaic but real terms is awe-inspiring. Of particular note are the "destriers" of Urth, which are carnivorous, fanged, and capable of charging at 90 miles an hour. The names of prehistoric animals crop up pretty often as well, but the notes in the back seem to indicate that these are not necessarily revived species (although the narrator seems to think they are) and might be whole new (but fairly similar) creatures.
In Gene Wolfe's Book of the Short Sun series, the "elephants" of Planet Blue apparently have two trunks.
In the Honor Harrington series, most species are named after terrestrial animals, but except for a very few cases these refer to indigenous species of other worlds that aren't very similar to their namesakes. Lampshaded in the short story "A Beautiful Friendship".
Treecats are sort of like domestic cats, sort of like ocelots, arboreal (as the name implies), intelligent, telepathic, and six-legged. They're stated in text to have a feline-like head, a body like a weasel or ferret (60 centimeters long), and a prehensile tail that is carried rolled into a tube or flattened for gripping.
A Hexapuma is like a big cat, only bigger and more dangerous. And six-legged.
A Kodiak Maximus is like a Kodiak Bear, only once again bigger and more dangerous. Presumably four-legged, since it originates on Gryphon and not Sphinx.
The "piggies" in Speaker for the Dead are (to grossly simplify their Bizarre Alien Biology) tree-climbing, scaly sentient beings with somewhat porcine snouts, by which, of course, the settlers of their planet chose to identify them. Of course, most of the Lusitanian lifeforms are given Portuguese "rabbit" names. For instance, the indigenous herd animals are called "cabra", Portuguese for goat, while the grass is "capim".
The 'horse' in Spider Circus. It's a lot like a horse, if horses were incredibly vicious, angry and ate people.
From the Ender’s Game series are the Formics, more generally known as the Buggers due to their resemblance to giant ants.
Neal Stephenson's Anathem uses this, in addition to its inversion Call a Rabbit a "Smeerp". Devices that are obviously cell phones and video cameras respectively are called "jeejahs" and "speelycaptors", but vegetables and animals of the alien planet on which the novel is set are named for their closest Earth equivalent and Earth Anglo units (feet, miles) are used.
"I saw a cat once. It was digging through a garbage heap in a back alley on Amenhotep IX. I disliked it. Please explain the similarities between it and me." "All right... both of you were in the back alley, weren't you?"
One of S.L. Viehl's Stardoc books featured small, fuzzy, very alien-looking, herbivorous animals ... which were immediately identified as "kitties!" by the heroine's little daughter.
The title creature in Theodore Sturgeon's short story "The Hurkle is a Happy Beast" has got six legs, the middle pair of which is essentially a pair of prongs it can rock back and forth on, and it turns invisible when anxious, among other things. The author happily calls it a "kitten" anyway.
Terry Jones's novelization of Douglas Adams's Starship Titanic opens with "'Where is Leovinus?', exclaimed the Gat of Blerontis, chief surveyor of the Northeast Gas District. 'No, I don't want another bloody fish-paste sandwich!'" The following paragraph explains that the terms "fish", "sandwich", "bloody", and "Northeast Gas District" are inexact approximations of alien terminology, before deciding to start over.
The "Gin and Tonics". It's stated that every race has a drink with a name phonetically identical to "Gin and Tonics", but wildly different. It's a reference to something that has got anthropologists and structural linguists very excited in the real world: that just about every culture that worked out how to distill drinkable ethyl alcohol on a widespread basis went on to name the resulting spirit "water of life"—whiskey, aquavit, vodka, ouzo, eau de vie, etc. (look them up!) Not so mysterious, since alcohol kills germs and one of its main benefits in early cultures was that it could be imbibed without the health risks of drinking unpurified water.
Also in Hitchhikers, every Earth animal seems to have a "mega-" equivalent on Arcturus, including the Arcturan Megadonkey and the Arcturan Megacamel. There's even Arcturan Mega-Gin, an essential ingredient of the Pan-Galactic Gargle Blaster, to go with all the Arcturan Mega-Critters. In accordance with this trope, it's worth noting that the Megadonkey, for instance, has six legs.
The venomous, bipedal, reptilian "horses" mentioned in the trope description are from Sheri S. Tepper's novel Grass. The novel specifically states they are nothing like Earth horses (nor are the creatures they hunt remotely like foxes), but for twisted plot-related reasons the (human) residents of Grass ride the "horses" to go "hunting" anyway.
In Cordwainer Smith's Instrumentality series, the inhabitants of Norstrailia have creatures which are bigger than houses, completely immobile, and produce an immortality drug that makes the inhabitants filthy rich. The creatures are called "sheep". Well, they were brought to the planet as regular old sheep, then they mutated...
Comes up in a serious way in From a Buick 8. Sandy yells at Ned that the thing that came out of the Buick's trunk was not a bat, that's just the closest analogue anyone could give for the horrid thing.
At the climax of IT, when the children behold Its true form, the best their frail human minds can come up with is "Giant Spider". But the benevolent cosmological entity that helps Stuttering Bill really is a giant turtle.
There's also the "chuck" from "Mrs. Todd's Shortcut". Okay, it was woodchuck-sized and furry. It also tried to eat a car.
A variant occurs in David Weber's Safehold books. The humans who have settled on the planet Safehold have named many local animals after mythical beasts. Examples include the kraken (described as a cross between a squid and a shark, fitting the latter's place in Safeholdian ecology), the dragon (a massive, six-legged animal that comes in both carnivorous and herbivorous varieties), and the wyvern (four-winged flyers that are the Safeholdian analogue of birds). There are also more classic examples—there are Safeholdian grasshoppers, narwhales, and sea cows. The grasshopper is a great example of this trope—the Safeholdian grasshopper can grow up to nine inches long and is carnivorous.
A non-animal example from the Antares novels. Altan coffee is described as tasting very different from Terran coffee. It is made from a native plant that the original colonists decided was the best local substitute.
Hell's Gate: Arcana has "Unicorns", which resemble the usual image of unicorns only in that they have a single horn and are roughly horse-sized and shaped. They are black, with disproportionately long legs, powerful hindquarters, and ears like a bobcat — and possess a mouthful of long tusks and sharp, carnivorous teeth.
There are carnivorous unicorns (more often called "One-Horns", but guess what unicorn means) in the Elvenbane series as well, along with mammalian shape shifting superintendent "dragons".
Asimov's novel Nightfall is preceded by a forward explaining that the characters, creatures, etc., are technically alien, but would be described in Earth terms to avoid Call a Rabbit a "Smeerp".
One of Shub-Niggurath's titles is "The Black Goat of the Woods with a Thousand Young". You'd be hard pressed to find anything less like a goat. It looks like this◊. Notice the people at the bottom of the image. Most depictions of her have some hoof-like protrusions in some of her tentacles. Considering that most who see her in the flesh don't survive, it's possible that she was named after the tracks she leaves when summoned. It is also possible that the "goat" appellation was a reference to its promiscuity—there are other places and situations where a libidinous individual or critter is called a goat—like a dirty old man being called a "randy old goat".
The Hounds of Tindalos are named mainly for their persistence in tracking down anyone whose "scent" they have picked up. Otherwise they're vaguely-described abominations that apparently hunt their victims through time, can materialize from any nearby corner they find, and presumably don't bear much if any family resemblance to canines as we know them at all.
In Larry Niven's Flight of the Horse, the protagonist Svetz is from a time where most animals are extinct, and he uses a Time Machine to obtain animals for the global zoo. Unknown to him, however, his "time machine" drifts across parallel universes as it travels, and he consistently winds up bringing back mythological creatures. As even "real" (i.e., nonmagical) animals are only known from sources like poorly illustrated children's books, no-one thinks it unusual that the "horse" he brings back is actually a unicorn (but they persist in calling it a horse, cutting off the horn to make it look more like the one in the book), or that the "gila monster" is actually a fire-breathing dragon. He does manage to acquire a regular whale... except that it's Moby-Dick in the flesh — complete with a dead Captain Ahab still in its jaws — and he had to avoid the Leviathan to capture it.
Botanical example: Khepri artists from Perdido Street Station chew a variety of berries to add color to the paste they sculpt. Colorberry varieties include blueberries and blackberries, but also redberries, yellowberries, etc. As khepri "blueberries" are described as tasting tart, not sweet, it's unlikely that they're the same thing as blueberries on Earth. (Either that or they aren't ripe. Or are "European blueberries", better known as bilberries.)
One smaller variety of predator from Henders Island is designated a "rat" by the researchers of Fragment, despite being as un-ratlike as a carbon-based life form is likely to get.
Hinted at in The Gnome's Engine, when the Duchess asks Jarl Skogsra about the Troll King's hounds. Seeing that she's looking at some huge ugly mastiffs, the Jarl corrects her: those are only the King's dogs, not his hounds. She would know the difference if she saw the latter.
Joy Chant's Vandarei books describe a nomadic people, the Khentorei. They ride large, powerful unicorns whom they call horses. ("Khentor" is possibly derived from "centaur" but that's neither here nor there.)
The Dragaera novels use elements of this trope, as Word of God holds that the "orcas" of Dragaera could use an Earth Orca (Whale) for a chew toy. The Dragaeran word for "hawk" is a special case, as it refers to diurnal birds of prey of any sort, and hence applies both to genuine hawks and to non-biologically-speaking-hawk birds of prey (i.e. Shrikes, Falcons, Ravens, Keas...)
Yulia Latynina's Inhuman features a character musing:
The fact that "Eden" got into the Protection Services' hands was known to at least two dozen people. And as the old phrase goes, "What's known to two men is known to a pig." The colonel didn't understand how a "pig", a self-replicating Loellian strain of algae used for food for the poor sections of the empire, could know know anything at all, though, perhaps the word "pig" meant something different in the past. From this he figured that over the centuries pigs have changed quite a bit, while people didn't.
In Arthur C. Clarke's story "The Wall of Darkness", Shervane and his father's traveling party includes "certain animals it is convenient to call horses".
In Ursula K. Le Guin's short story "Paradises Lost", the colonists of a new planet (who are just off the Generation Ship where they've lived for several generations) dub a certain kind of insect a "dog". They know it's not what the word originally referred to, but no-one's ever seen a dog, so no-one cares.
In the Liaden Universe, Borrill, Zhena Trelu's "dog" on Vandar, doesn't look anything like a "dog" as Val Con or Miri know them, but is called a dog by the narrative (and Val Con theorizes that it fills the same ecological/cultural niche on that world).
Toto, the alienpet in Helen Weinbaum's short story "Honeycombed Satellite," is a three-legged creature with a roughly tetrahedral body, a simian face, rabbit-like ears, and a habit of parroting any sound that he hears. He's also photosynthetic. The main characters nonetheless insist that he's a puppy.
The clovers in Horton Hears a Who! are all portrayed as being large, pink fluffy flowers. Which is what an actual clover flower looks like in real life. While most people associate "clovers" with the three or four-leafed plants, there are pink and white flowers that grow in association with them.
The Diana Wynne Jones short story "Nad And Dan Adn Quaffy" features an author who includes in every book some version of coffee. The names get steadily more exotic as the story progresses.
The Stormlight Archive has "axehounds", which while apparently dog-like in behavior, anatomically most closely resemble giant arthropods. A man from another planet lampshades this, noting that while the natives are well aware of what an axe is, they have no real hounds, making it in-universe Orphaned Etymology.
The Clockwork Rocket by Greg Egan takes place in a universe with entirely different laws of physics from our own. It still uses common words like "plant", "forest", and "wheat" to describe the things that are roughly analogous (never mind that plants gain energy by emitting light rather than absorbing it).
Used to an extent in John Carter of Mars; Carter tends to describe the Martian fauna by comparing it to the closest Earth equivalent, but most of these creatures do have their own names and are described up-front as being alien-looking. Interestingly, the novels use the terms "man" and "woman" to refer both to members of the various humanoid Martian subspecies as well as the decidedly non-humanoid Green Martians.
Tunnel in the Sky features high school students stranded on an alien world during a survival test. Most of the native animals and plants are given Terrestrial names for simple identification. For a time, recovering from a near-delirious daze, Rod convinces himself that they never left earth and that the lion-like creatures were lions. The primary exceptions would be the noisy, nocturnal "grand opera" and the goofy, harmless "dopy joes".
In Ssalia and the Dragons of Avienot, the Lizard Folk-type ssyrean are sometimes referred to as "snakes" (possibly to "translate" a term from the original (hypothetical) fictional language into a more familiar one). They do have similarities, but being humanoids (with limbs), they aren't exactly an equivalent to the serpents found on Earth.
One early scene in China Miéville'sEmbassytown all but outright states that human colonists habitually do this to the native animals of colonized worlds, and that the alien creature refereed to as a rabbit on one world may bear as little resemblance to the alien creature refereed to as a rabbit on another as it does to an actual rabbit.
Scile: "That's not what we call a dog where I come from"
The Rifter: "Weasels", egg-laying mammals of Basawar. Basawar and our world (it is possible to cross from one to the other by a magical gate) may have been connected at some times in the past; they share some flora and fauna, but not all — there are dogs (actual dogs) but no cats in Basawar for example.
Wolves Fates Road are not wolves. They are humans who have mutated into somewhat deformed bipeds with vaguely wolf-ish faces.
Calling Targs (spikey warthog-looking things) and Sehlats "cats" (or "kitties") comes to mind. The Sehlat is also called the Vulcan equivalent of a teddy bear, despite not appearing all that similar to a terrestrial teddy bear. It's alive, for one thing. As Spock was quick to point out (when McCoy seemed amused that he owned a "teddy bear" as a child) it also has six-inch fangs. According to the animated series and Enterprise, Sehlats resemble a cross between a polar bear and a smilodon, and they are quite large.
In Star Trek: Enterprise, Dr. Phlox mentions the "Denobulan lemur". He goes on to clarify that "most have only one head".
In Stargate SG-1, the Goa'uld Puppeteer Parasites are frequently called "worms" or "snakes", though those are derogatory terms not meant to be descriptive. For a start they are vertebrates, therefore they aren't worms. They also have fins, and when not engaging in parasitism their natural habitats are bodies of water—so they are closer to eel-like fish (though with three eyes distributed around the head).
In the Book of Revelation (also called the Apocalypse of John), there are creatures called "locusts" which have human faces, lion's teeth, breastplates of iron, giant wings whose flapping sounds like an army of horse's hooves, and stingers which cause victims to experience several months of solid pain. They're also explicitly described as doing absolutely no harm to plants which is the opposite of what actual locusts do. That's one of the book's quirks.
What are referred to as rabbits throughout The Bible are most likely hyraxes, small creatures native to Africa closely related to elephants. European translators of the time had never heard of a hyrax, so they substituted a more familiar animal.
In modern Hebrew, the word for hyrax (shafan) is used for rabbit much more often than in the original meaning.
Many Greek translators turned Leviathan and Behemoth into crocodile and hippopotamus. See the descriptions in Job as the "Crocodile" starts breathing fire and the "Hippopotamus" has a body Job cannot even comprehend beyond its tree breaking tail.
Leviathan is the current Hebrew word for whale. And Russian still uses Behemoth as a word for hippopotamus.
Although the concept of "pareve" in Judaism actually means "neutral, doesn't count as meat or dairy for kashrut purposes", many popular works will simply say that for purposes of dietary law, fish (if kosher) are a vegetable.
Judaism also classes all water-animals—including crocodiles and turtles—as fish, which may be where Christianity gets some of its odder classifications RE: Lenten fasts (it's usually attributed to Aristotle, but no, Aristotle not only knew those weren't fish, he also knew whales weren't fish).
A similar treatment was given to Seawolves (an old term for pirates), spider-monkeys (they really look disturbing), and wolf spiders (who had wolf heads). However, since these are all cases of exactly what it says on the tin, it does raise the question of if we should count examples that make sense.
The Talislanta game flirts with this trope, featuring "equs" (pseudo-Latin for "horse") as the most common riding beasts. Equs in Talislanta are reptile/mammal hybrids with claws, scales, manes... and (for the darkmane breed) a propensity toward foul language. Yep, the "horses" talk.
BIONICLE often used this, mostly in its early years:
Tarakava are referred to as water-dwelling lizards, when they have nothing aquatic about them (their box cover even shows them in a desert environment), what more, their immense punching arms, freaky and blocky heads, stick-like mid-sections, not to mention having tank threads for feet don't quite make them look like lizards either. The Tarakava Nui, AKA "King of Lizards'', took this further, and ended up looking like mechanized, boxing totem poles◊.
The Hapaka is said to be a dog, whereas the model looks like a miniature elephant, with a trunk and tusks and all.
Muaka is a tiger that has a dog-like head, also has a caterpillar track instead of back legs, and can extend its neck. Its only tiger-like aspect is that it has some yellow on its black body. The Kane-Ra bull, which is the same model but with a few minor aesthetic differences, at least has horns to make it resemble the animal it's meant to be.
Kuma-Nui. Basically a gigantic Muaka, but with two tank threads instead of one, a built like that of a gorilla, and an enormously long tail. It's a rat.
The Fenrakk spider, at least the "main" model (not the alternative variant sold with the playsets), has no actual spider-like traits, besides having pointy legs. It looks rather like a quadrupedal dragon.
Sea squids, the species used as Abnormal Ammo by the Barraki, are really leeches, even in their feeding habits, that look nothing like any kind of squid. They don't even have tentacles.
Shadow leeches, on the other hand, are more difficult to describe... they look like cheesy video game enemies◊... but at least behave like leeches, and according to the story, have long tails that unfold, unlike in the sets.
Left 4 Dead plays with this trope. The Survivors avert Not Using the Zed Word hard, and call the zombies zombies. They give names like Witch, Hunter, and Smoker to various unique horrors ("special infected") which inhabit their world. Each special zombie has common features and distinct behaviors. They're also high priority targets and major threats. Survivors and players both use the common nicknames of the zombies to quickly identify them. Where this trope comes in is with the very prosaic names. A zombie which spits a glob of flesh-melting acid a hundred feet, allowing it to fill a room with deadly slime? Just call it "Spitter."
Pictured above (from the Animated Adaptation): the Tiger isn't a tiger. It's a wolf. And even then, it's not even a normal wolf — it has blue fur, a fluffy mane, and horns. Cue much confusion for the players. For the record, the name is a translation error. The original name sounded a great deal like "tiger" and so it stuck. If translated right, the name (Taiga) would even reference his ice abilities.
Speaking of Japanese names, Hare the rabbit monster is called Ham in Japanese (like a hamster, even though it clearly is not)
Baku also doesn't have a strong resemblance to the tapir it's named after (or even the Youkai the tapir is named after in Japanese), looking more like a giant plush dog.
Starcraft II gives us Zerg "Roaches", 10 foot long acid spitting organic tank beasts, and "Vipers", gigantic dragonfly-esque flying monsters whose tongues can snare enemy tanks as easily as frogs catch flies.
The Frog and Rat creatures from obscure action-adventure game Sphinx And The Cursed Mummy resemble neither frogs nor rats. The Frog has scales and a tail, can stand on its hind legs, and has a bright red crest (though it still hops like a frog), and the Rat is covered in razor-sharp spines. It also has a weird, dachshund-like body.
Due to Cultural Translation, Kapp'n the cabbie/bus driver/boat rower from Animal Crossing is called a snapping turtle, and occasionally, a parrot. He's actually the mythological Japanese Kappa, as is made obvious by his name. Tom Nook from the same game also suffers from a tanuki-to-raccoon species change.
In one sidequest of Mass Effect 1, you have to find a data module stolen by creatures that act like monkeys, sound kinda like monkeys, and are called monkeys... but sure as hell don't look like monkeys. And then there are the Space Cows. One is even shifty-looking... and will rob you when you're not looking.
Note that the monkey-like species is called "pyjak" in the second game. They are very common on the planet Tuchanka, homeworld of the Krogan. However, Wrex will never actually correct you in the first game when you refer to them as monkeys. While they are common, they aren't native. Some traders left a bunch of them at port, and even the voracious Tuchanka ecosystem hasn't managed to stamp them out.
Final Fantasy XII is also guilty. Real wolves and hyenas have a distinct lack of horns and tusks.
And alligators do not have a three-part jaw. Or fur. Or exoskeletons, though that bit isn't obvious unless you actually read the bestiary entry. Those bestiary entries also seem to think that carnivorous horses with tentacles are perfectly normal. Or chibi-style rabbits with feathery ears (some of them even have four ears) and a fluffy ball-like tail which is about the size of their body. While the Panthers do appear like big cats with dark fur, they're Coeurl-class enemies and so have a couple of tentacles growing out of their backs.
This has been going on since the first Final Fantasy I game; the NES version referred to underwater scorpions as "Lobsters".
Final Fantasy VII has Fort Condor, a mountin/fortress with what looks like a giant bronze bird statue on top. But go inside and talk to it reveals that even the main characters already know that yes, that is a real bird and no, it doesn't look out of place despite the fact that it's the size of the power reactor on top. What's it called? Well, a Condor, which is why the fort is called a Condor. It doesn't even move for the majority of the game, guarding its nest... a reactor. It layed one egg that's probably half as tall as the reactor and sits neatly in what looks like one of the reactors big chimneys to keep it warm. After completing the sidequest, the party gets to watch the egg hatch, and it does, in the process of creating the totally natural reaction of encasing the entire reactor in an energy field, leaving the parent trapped, then blowing up, killing the parent you were guarding the whole sidequest and after the baby "Condor" (still large enough to squash a human by stepping on it) flies away is a materia you can use to summon the mythical phoenix, further proof it isn't any old Condor.
In the Tales Series, if it's a monster and it's named after a real animal, don't expect it to look much like said animal. The most common example of this are the wolves, who aside from their canine body shape generally look more like reptiles then anything else.
In Tales of Symphonia, Lloyd insists that Noishe is a dog, despite the presence of real dogs that look nothing like him. The rest of the world either lampshades this or just plays along. This is, however, justified: Lloyd reveals in Heimdall that he calls Noishe a dog because he knows that he's not a wolf, so he just assumed he was a dog. We later find out that Noishe is something called a protozoan... but he doesn't look anything like our protozoans either. Noishe is called protozoan because of its legend. It is the "first animal". If you know Scottish mythology Noishe is a (type of mythological) dog. His name is pronounced nearly identical to "Cu Sith" (Pronounced Cu Shee), and he matches the physical description of one.
They also have a large, furry, bipedal and somewhat troll-like monster that could legitimately have been called a Bigfoot, a Troll, or possibly a Bugbear. It's simply called a Bear. The Palette Swap of it, encountered later in the game, is an Egg Bear, compounding the nonsense.
The sequel: Dawn of the New World actually justifies this by introducing a large canine monster that bears a strong resemblance to Noishe... then it introduces the Griffin as a monster with only two legs and a wolf-like head.
Likewise, the "Ligers" in Tales of the Abyss are massive green-and-purple canines that shoot lightning and reproduce by laying eggs. They are also hinted to be matriarchal in nature.
The "rats" in Chrono Trigger's 2300 AD bear only vague resemblances to their real-life counterparts. Since most creatures in the future are mutants, though, this might be justified.
Antlions! The only example in a series full of alien creatures. Also, the antlion Hive Guardian is referred to by the vortigaunts as the "myrmidont", which is derived from real-life antlions' scientific name (Myrmeleontidae). Also, they have a King instead of a queen, for variety.
Also featured is Dog, a huge, gorilla-like robot... Who does act like a dog would, if it were in actuality a huge, gorilla-like robot. It's implied that it used to look more dog-like until Alyx added on to it.
There's also Xen's barnacles: saggy bags of flesh with a tentacle... relatively appropriate appellation though.
Zeno Clash contains "wrathbirds" and "squirrels". The squirrels are very similar to real squirrels, but the wrathbirds that look nothing like a bird, and share the elongated ears and large rear paws of a rabbit.
One race of aliens called the Kig-yar are also named "jackals", because everyone knows jackals are not small dog-like canids but humanoid... bird... things. This is what they look like.
The flightless birds on Reach are named moa, after the extinct real-life species. The latter were 12 feet tall and completely wingless, while the Reach birds are smaller and have rudimentary wings.
Dwarf Fortress: A bunch of goblins are knocking on our door riding beak-dogs? Okay, dogs with beaks ain't so bad — Urist McHammerer, take 'em — OH GOD, WHO LET THE VELOCIRAPTORS IN THE DOOR!? As this is simultaneously a mundane-sounding name for an exotic creature and an unusual name for an earthly creature, this doubles as Call a Rabbit a "Smeerp", a rare achievement.
Additionally, Fluffy Wamblers are often called "sheep" by players, despite being humanoid agricultural pests 1/3 the size of a cat.
Not a definite case, since no pictures or descriptions are provided, but some of the creatures in Rogue might be this. What sort of emu lives in a dungeon?
Common in older JRPGs due to name space constraints and/or poor translation combined with the reuse of sprites. The Final Fantasy Legend features the Wolf and Jaguar, but both monsters use the same graphic of a tiger. Okay, so at least one of those is another type of big cat.
Most Pokémon actually have real animal names for their species names.
For example, Pikachu is the "Mouse Pokemon".
Some of these are particularly stupid, like Sandslash being called a mouse when it is clearly a pangolin.
Cradily is called the "Barnacle Pokemon", despite being based on a crinoid, which are in an entirely different phylum.
The most ridiculous of these would likely be Blastoise, a giant turtle, being referred to as a shellfish.
Some of the actual names are pretty bad too. Houndoom/Houndour are named after Hounds but are pretty clearly dobermans (that breath fire, but that's where "doom" comes in). There's also the pokemon Golem, who evolved from a rock with a face to a boulder with a face, but aside from being rocky has no resemblance to the mythical Golems (and there are actual Golem pokemon too). Psyduck and especially Golduck bear a much closer resemblance to Platypi then ducks.
Also happens in the japanese names. Charmeleon, the fire breathing bipedal salamander/chameleon with a tail perpetually lit? That's called a Lizard.
In Digimon, the obviously rabbit Patamon is called a mouse, as well. Then the rodent Cartoon Creature is called Opossumon and it behaves like a cat.
In Mabinogi, The southern region of the continent of Iria (which is a cross between Africa, Australia, and the American Southwest) tends to scale up their animals and tweak them to look more like other animals (such as fennec foxes that look like large hyenas from behind, and mongooses that are two feet tall at the shoulder). Compare the original continent of Uladh (loosely based on ancient Britain), which uses smeerps sparingly (with the exception of Dire Whatevers).
The entire franchise has examples of this. "Imps" for leathery spiny fire breathing humanoids? "Demons" for monsters like rampaging shaved gorillas?
Imps and demons don't really exist in real life, so there's no concrete frame of reference to compare them to. Not to mention that, seeing as you're up against the legions of Hell, "demon" is a pretty accurate term for pretty much anything you're fighting that's not a zombie.
Most of the higher-level monsters had fairly unusual names, especially in Doom II but the novels played this trope to the hilt, throwing in "Pinkies" and "Pumpkins", along with other non-animal designations of "Clydes", "Bonies" and "Fire eaters" amongst others.
Maggots (two-headed crawling demons) and Ticks (exploding giant spiders) in Doom 3.
Touhou: Most youkai in Gensokyo appear as if they were youkai in stats only. Check out the Cute Monster Girl entry.
There's also the use of "youkai" as a catch-all term for supernatural beings, including some more distinctively western creatures like the Scarlet sisters (European-style vampires).
Yoshi's Island has Poochy, a sort of... canine/amphibian hybrid thing with huge lips, no ears and a tongue nearly the size of the rest of its body. It's simply referred to as a "dog" in-game.
The ghost dog in Luigi's Mansion: Dark Moon is also similarly shaped to Poochy, including the lack of ears. It seems that dogs in the mushroom kingdom are ear-less animals.
The Barracuda Sharks in Quake II more resemble deep-sea viperfish than either of the former. The Hornet is a giant half-insectoid half-humanoid flyer.
Septerra Core. Certain monsters — especially Thunder Cats (which, in spite of vaguely feline gait and ecosystem role, look more like stone rhinos) and various things marked as spiders and beetles which look very little like their Earth equivalents.
The Lemmings in Lemmings actually look more like humanoid green-haired creatures than actual lemmings, which are rodents. The only similarity is the fact that both actually tend to walk off cliffs to their deaths in huge groups. Apart from real lemmings, that don't.
Several enemies in the Chaos Rings series are like this, with the dolphins◊ being one of the most bizarre. The games explain it as these monsters, called congloms, are created by from the DNA of terrestrial animals, but that doesn't really explain why they aren't given new names.
Xenoblade skirts this and Call a Rabbit a "Smeerp" in it monsters (at least in the English release), many are variants of normal animals with variations of normal animal names. To wit, Antols are ants the size of a dog, Brogs are large frogs with armored scales on their backs. There are also Ponios, Skeeters, Krabbles, Piranhaxes, etc.
Be honest; most of the Sonic the Hedgehog characters really don't resemble the animals they are named after all that much, especially the hedgehogs. And while we're being honest, Doctor Robotnik doesn't really look all that human.
In Pikmin, Captain Olimar crash lands on a strange world and comes up with names - common and scientific - for many of the plants and animals. A whole family of creatures get christened "Bulborbs" because Olimar thinks they look like his pet dog, Bulbie.
Borderlands and Borderlands 2 feature spiderants, massive four-legged insects with tough exoskeletons. While they seem to have a "society" somewhat like ants, physiologically they have little in common with spiders or ants (and, really, any real-world insect or arachnid you can name).
In EtrianOdyssey most of the monsters are named after real life animals, so you have chubby green Hares, white and purple Mantises with pink wings, Largeants that look more like spiders with a skull for a face, Sloths that more closely resemble a gorilla, and so on...
The Elder Scrolls V: Skyrim has mammoths with two pairs of tusks (it stands out, as the other two almost-but-not-quite-Earth animals have Smeerpy names). It also continues a mineral variant of this trope, with ebony being a hard mineral rather wood, and malachite, quicksilver and moonstone being similar to their Earth selves, but much more useful for smithing.
The quicksilver (mercury) is used in the form of ingots. Apparently Skyrim is much colder than it looks. Also, the corundum is a coppery-looking metal rather than rubies or sapphires (and in Real Life, the metal you can get from corundum is silvery—since it's aluminum).
Murfy from the Rayman series. Officially speaking, he's a greenbottle fly. However, his design goes to such Cartoon Creature extremes (he only has four limbs instead of six, for example, seems to have skin instead of an exoskeleton, and to say nothing of his huge and perpetually grinning mouth) that he's more often taken for some kind of flying frog than a fly.
"Flint stones" in Clonk are spherical, bright red, and explode when they hit a solid surface.
Guild Wars 2 has winged lizard creatures with long tails that it calls "bats". The use of this trope is even stranger because in the previous game there were called "incubi".
Cubivore's pigs, bears and birds are nothing like the animals we know, especially not the birds.
Shin Megami Tensei IV has the protective warriors of the Eastern Kingdom of Mikado who don Western-looking garb and weapons. Despite this, they're called "Samurai". It makes a slight amount of sense when you consider that Mikado was built on top of Tokyo.
El Goonish Shive has Jeremy the "cat". That's Jeremy "the creature that nature never intended", in fact actually. Although, given his behavior, he might as well be a cat. Word of God'' claims half-cat, half-hedgehog.
The pet "bird" of Spatch II in Rice Boy. Has no beak (but a small forked horn instead), neither arms nor wings, sits on his swing like a human, and says: "Fuh!"
The Bull from Tower of God. Which looks nothing like a bull. It's more like a giant bipedal newt whose head has evolved similar to that of a flounder, except that it still has an eye on each side. Furthermore, it has a lure like an anglerfish to attract in curious people and has a skin cape growing from it's back. And the scariest thing is, it eats meat and has opposable thumb enabling it to wield a big-ass lance which it uses to hunt. So clearly, this is nothing like a normal bull.
The wildlife of Tethys in Harbourmaster has some similarities to Earth life. Thus, the colonists gave them names that approximated what they seemed like. For instance, there's the wolf shark, a shark-like creature that hunts in packs like wolves would. Not used for naming were the orca-like patterning and their use of electrical pulses for both communication and attack.
Sythyry's Journal references a character's "horse" a few times, then makes some comments about said horse pecking at people with its beak.
This series zig-zags furiously. It takes place in a distant future where humanity as we know it doesn't exist. While the space weredog member of the duo likes dog-related idioms — turning "carrot and stick" into "treat and (rolled-up) newspaper", for example —, several items seem similar to their usual variants, at first. But "doorknobs" are apparently touchscreen devices that can be hacked, and windows have sliders to control their opacity instead of shades or curtains. Amusingly, uncoffee doesn't exist; several alien races with precognitive ability exported coffee off-earth before humanity died.
Cecil's descriptions of Khoshekh or cats in general don't sound like anything understood under the word outside of Night Vale. Deadly poisonous, his meow is a horrible screech, doesn't purr or acts much like a cat etc..
"Penguins" in have four wing-flippers and mammalian noses and whiskers instead of beaks. This example is made odder by the fact that most of the animals in the series have hyphenated names to reflect their mixed-and-matched features. They're called otter-penguins according to the supplemental bookThe Lost Scrolls: Water.
There's also the sky bison/wind buffalo, which look like giant, six-legged bovines, which brings up the question of how they fly. The answer is that they were the original Airbenders, like badger-moles were the original Earthbenders.
Momo, who looks like a mix between a monkey and a bat is just a "lemur" in the series, and a lemur-bat in the movie.
Rhinos, which look like a mammalian version of a triceratops.
When the protagonists get a chance to see a no-modification, no-special-abilities, completely ordinary run-of-the-mill bear, they become genuinely confused.
The "Hornet" monsters (also called "Frelion") in Code Lyoko are green, ten-winged, spike-mouthed, poison-spitting digital beasts, and aside from their "stingers" (which shoot Frickin' Laser Beams), they aren't very hornet-like. Similarly, the monsters called "crabs", while red and flat, have four long, spindly legs instead — though their name is spelled "Krabe", despite its pronunciation.
Eventuallylampshaded in Season 2 when Odd dubs the new monsters that slaughtered the team "tarantulas"; when Yumi responds in confusion, Odd repeats his name choice and says that he likes for his enemies to have names.
Cerbee from Jimmy Two-Shoes. Everyone refers to him as a dog. He barks like a dog, is named after a dog, and does several dog things, but he's a small, one eyed horned monster who, other than having four legs, looks little like a dog.
Also the Weevils. Real weevils are a type of beetle. The weevils in Jimmy Two Shoes are furry chipmunk like rodents. There is actually a reason behind the name-it's a combination of "weasel" and "evil".
A version of this appears in a episode of Young Justice. One alien character is named for an animal which does not exist, but he decides that he shall be called Wolf. Superboy immediately defies this trope this by introducing the alien to his wolf named Wolf. Then the alien decides on the name "Bear".
Very small children invoke this trope all the time, calling pretty much anything with fur either "doggie" or "kitty", and anything with wings a "bird". It's called "overextension".
Contrary to popular belief, the scientific ordering and names of various flora and fauna are not set in stone. They can and are subject to changes depending on new research, and animals once thought to be related to another can later be considered unrelated at all, which can invoke cases of this trope.
Whether the large, wooly bovines of North America are called "bison" or "buffalo" has caused more than one heated debate in its day. However, "buffalo", though once deprecated, is becoming seen as acceptable again. After all, American bison were first called "buffalo" (from French "boeuf" meaning "ox") in 1635; the term "bison" (from Greek "bison" also meaning ox) was first used for them in 1774. While they are certainly more similar to European bison, they're nearly always called "buffalo" in the regions where they're actually found—which is what "common name" means—and the binomial nomenclature prevents there being any confusion among zoologists.
When American settlers first encountered what Europeans generally refer to as "wapiti" (Cervus canadensis) in North America, they called it the "elk", since they deemed it closest to that European deer in appearance and size. However, when they encountered the same species that Europeans call elk (Alces alces), they used the Algonquin name "moose". To further complicate matters, C. canadensis is closely related to and is sometimes classified as the same species as the European "red deer", C. elaphus (though the Red Deer is somewhat smaller). Even so, it seems both cultural spheres have kept their respective namings to the present day.
American Pronghorn Antelope are no more related to Old World antelopes than to goats, deer, and cattle, though they do share a certain resemblance. They are, in fact, the last remnants of an otherwise extinct uniquely American group of animals.
The pronghorn family, Antilocapridae, is a sister group to both the Cervidae or "deer family" and to the Bovidae, which includes cattle (including buffalo and bison), goats (including sheep), and the various other kinds of "antelope". And giraffes. The "antelopes" of the Old World are typically no more closely related to each other than to other Bovid groups like goats or cattle.
Red pandas, a.k.a. firefoxes, are neither foxes, nor relatives of the giant panda. Not called "red raccoons", despite looking quite a bit like exactly that, because it's only in the last few decades that non-Americans even knew what a raccoon was (or at least didn't think of them as every bit as exotic and not-a-basis-for-comparison as, say, kangaroos).
On the other hand, giant pandas have flip-flopped on this trope. Originally thought to be bears, their unusual coloring and lifestyle led some to conclude that they must be instead related to red pandas and thusly, according to the knowledge of the time, to raccoons. Thanks to genetic testing and other newer techniques, it's now known that neither species is part of the raccoon family. Giant pandas are now firmly acknowledged as bears, while red pandas are placed in their own family, Ailuridae (and are more closely related to weasels than anything else).
European explorers did this a lot when they came to Australia.
Koala "bears" are marsupials, not bears. Australians (and many other folks, too) usually just call them "koalas" now.
The echidna was originally called the spiny anteater (it does eat ants, but it is unrelated to the animals known as anteaters).
Rottnest ("Rat Nest") Island in Western Australia was so called because a Dutch explorer thought the quokkas (small kangaroo-like marsupials) there were rats.
There are no alligators in the Alligator River. There are, however, plenty of crocodiles.
Guinea Pigs, being small furry rodents, have no actual relation to pigs; this was used for comedic effect in a 1954 Disney short, Pigs is Pigs. It's generally held that domestic cavies were first called "guinea pigs" because they were commonly kept (on ships, which used them as food supplies while at sea) in enclosures resembling miniature pig-pens; they're also built like pigs and make many similar noises. The German name for them, "Meerschweinchen", actually means "little dolphin", "Meerschwein" ("sea pig") having been the older German word for dolphin. In Peru, where they were first domesticated, it was as a meat animal—which is no weirder than raising rabbits for meat (indeed, the most common Spanish name for them is "conejillos de Indias", "Indian bunnies").
Porcupines got their name from the Middle French porc espin ("spined pig") since their body shape and snout resembles that of pigs, but they're actually rodents. Fortunately, most people know this.
Hedgehogs aren't related to pigs. Their name dates back to the Middle English of the 15th century; it was known as heyghoge, and called such because it was frequently seen in hedgerows (heyg), and had a snout like that of a pig (hogge). This one is clearly still relatively common knowledge, to the point that their name has changed spelling to keep up with the modern versions of the words "hedge" and "hog".
Groundhogs (also known as woodchucks) are rodents, not pigs, but were called that because their burrowing habits were reminiscent to pigs. Their very names are even subject to lingual limbo: "groundhog" is a transliteration of the Dutch word aardvark (itself a name for an animal which is unrelated to pigs, but named such for the same reasons as groundhogs). "Woodchuck" doesn't actually refer to chucking wood, but is derived from the Algonquian name for them: wuchak.
Prairie dogs were given their name by French explorers, but they're small burrowing rodents, and look nothing like dogs. They were probably named "prairie dogs" because they can bark like a real dog, though. Even the genus of their scientific name, Cynomys, is Greek for "dog mouse."
The tanuki suffers from a bit of this, often being misidentified as a raccoon or a badger. Its name in English is even raccoon-dog (they're canids).
When Chinese explorer Zheng He brought a live giraffe back from Africa in 1414, Chinese scholars identified it with a mythological beast called the qilin, based on some superficial similarities between the two. Post-15th-century representations of qilin in art look a lot more like giraffes than the original creature, a chimera with the head and horns of a dragon and the body of a horse. In Japan and Korea, giraffes are still known as "kirin" to this day.
Hence, the PokémonKirinriki (it's a palindrome in the original Japanese characters (キリンリキ), just as its English name Girafarig is a palindrome).
The Japanese name for the tapir is "baku", after a dream-eating mythical creature that it very vaguely resembles. Most modern portrayals of the mythical baku are simply tapirs outright, only with the abilities of the mythical creature.
Hares aren't considered part of the group of genera as other rabbits, though they're all still in the same family — hares don't burrow and aren't born blind or hairless. That means, technically, "jackrabbits" (another name for hares) is a misnomer, but that's just splitting hares.
Tasmanian Tiger/Wolf: A very recently extinct animal that got the name "tiger" for the stripes on their back. These wolfish creatures are actually marsupials.
Sabre-Toothed Cat: Originally coined the Sabre-toothed tiger, they have no relation to modern day tigers other than being cats.
Many people assume that any creature whose genus name ends in "-saur" must be a dinosaur, but this isn't true:
Pterosaurs, usually generically called pterodactyls, aren't dinosaurs, but archosaurs—diapsid cousins of dinos like crocodilians. If you want a real look at a winged dinosaur, look at a bird.
The same also applies for marine reptiles like sauropterygians (the famous plesiosaurs+ pliosaurs+ nothosaurs+ placodonts) and ichthyopterygians (ichthyosaurs+ thallattosaurs). Sometimes Dimetrodon is also called a dinosaur, but it turns out that it isn't even a reptile (at least, it isn't in any of the modern reptile groups), but actually an early relative of mammals.
Adding to the complexity is the fact that if it's big, scaley, and extinct, people call it a dinosaur, when none of those terms really refer to dinosaurs (there were a few in a very brief period that were big, most were between the size of a large dog and a cow; they had feathers, not scales; and they're not extinct, we just call the living ones "birds").
Early explorers, biologists, and colonists named many North American birds for their resemblances to Old World species. When Science Marched On, more than a few resemblances proved superficial ...
The American Robin and its relatives in other parts of the New World were named by colonists for the European Robin, probably due to the red breasts on both birds ("Robins" are more archaically known as "Robin Redbreasts"). Later, biologists classified both birds (and their related species) as thrushes, but recently the European Robin and its Eurasian cousins have been put in the family of Old World Flycatchers (which are, in turn, not very close relatives of New World Flycatchers), though the New World birds called robins are still classified as thrushes (all of which fit into the Turdus genus; other New World thrushes, with the exception of bluebirds and solitaires, tend to be explicitly called thrushes).
New World Orioles (family Icteridae) were named for the Old World Orioles (the mostly African family Oriolidae)—as with the New World Robins, it was likely due to similar appearances.
Also in the Icteridae family: American Blackbirds (genus Agelaius). They were named for their predominantly black colors, much like the Common Blackbird, a European thrush who is therefore a relative of... the American Robin, even sharing a genus with it.
Another group of Icteridae members, the Meadowlarks hardly look like a real lark (of which there is only one species, the Horned Lark, native to North America; Europeans call it the Shore Lark)—but it sings like one.
Certain parts of the Americas also refer to vultures as buzzards. This is an old name for birds of the genus Buteo, which includes such species as the Red-tailed Hawk and its relatives, none of which look anything like vultures. The word hawk, in turn, traditionally referred only to the smaller, bird-hunting Accipiters, such as Goshawks, "Sharpies", Sparrowhawks, etc. To make matters even more confusing, the North American buzzard/vultures (family Cathartidae) bear only a superficial resemblance to the old world vultures; they are closer kin to the Andean and California Condors than to their bald-headed namesakes.
The American Kestrel used to be called a Sparrow Hawk, but its name was changed to recognize its closeness to its European cousin, the Common Kestrel, as well as the fact that it is a falcon (the smallest and most common in the United States, to be exact) and not a hawk (going by both the New World definition of Buteo and the Old World definition of Accipter).
Subverted with the American Goldfinch and other goldfinch species found in the United States — they share a genus, Carduelis, with the European Goldfinch much as the American Robin and Eurasian Blackbird are both in the genus Turdus.
New World sparrows are in the family Emberizidae like Old World buntings (and a handful of New World ones like the Snow Bunting) rather than Passeridae as with Old World species. However, some New World emberizids Take a Third Option and are called juncos or towhees. In turn, most New World buntings are actually in the cardinal family, Cardinalidae.
This occasionally happens outside the Americas as well. The Dunnock is sometimes referred to as the Hedge Sparrow, but it is not in the family Passeridae as true Old World sparrows such as the House Sparrow (which eventually ended up among the Old World species introduced to North America) are. However, one that stuck was the Java Sparrow, which is actually an estrildid finch (family Estrildidae), though to be fair estrildid finches are fairly close relatives of Old World sparrows, and it's possible that it used to be considered to be a true sparrow but changed families much as how the European Robin changed families. In addition to their relationship with estrildid finches, Old World sparrows are also more closely related to weavers (family Ploceidae) than New World sparrows, and older sources often placed them in the same family (occasionally leading to cases of Call a Rabbit a "Smeerp"), though typically they are considered separate families nowadays.
Similarly to the Dunnock, grackles (yet another group of members of the family Icteridae) are often informally referred to as crows in parts of the Americas that do not have true crows. However, American species of true crows, such as the common American Crow, are in the same genus as Old World crows such as the Carrion Crow (the same genus also includes ravens and other species such as the Rook).
The now-extinct Great Auk was the original penguin and is a flightless member of the family Alcidae, which also includes extant species such as auklets and puffins. Then this trope was applied to some Southern Hemisphere birds that resembled it but aren't close relatives of the auk family and the rest is history.
The French word for "turkey", dinde, comes from poulet d'Inde, "Indian chicken". They just kept the naming convention developed when the first European explorers to North America were convinced they'd reached the eastern Asian shore. That's why Native Americans are still referred to as "Indians", for instance.
The English word for "turkey", by the way, derives from the country of the same name—the name comes from the early modern English tendency to give anything from the New World a name with an "exotic" connotation, no matter where the animal came from. These American birds were thus called "Turkey fowl" and eventually just "turkeys," since Turkey was seen to be as exotic as the Americas. Indeed, most languages use some equivalent of either "Turkey fowl" or "India fowl" for turkey; witness Arabic dajaj Rumi ("fowl from Anatolia"—i.e. Turkey)note This one's particularly convoluted, since "Rumi"originally meant Roman; eventually it specifically meant Eastern Roman, and then referred to the land forming the bulk of the Eastern Roman Empire—Anatolia. and Turkish Hindi ("Indian", a shortening of a longer phrase meaning "Indian fowl").
In the Old World, screech owl is another name for the Barn Owl, which is the most widespread member of the family Tytonidae, which is sometimes called the barn owl family. However, in the New World, screech owl refers to members of the genus Megascops, which tend to be much smaller than a Barn Owl (the common Eastern and Western Screech Owls are both no bigger than an adult's fist, while the Barn Owl is much larger than they are) and are also in the family Strigidae like most other owls (and is also the family of all owls found in the United States except for the aforementioned Barn Owl).
Originally, "fish" meant "any water animal", and any animal that lived in the water was fair game to be called a "fish" (for example, jellyfish, starfish, etc.). Then, when scientists better understood how these creatures are related to one another, they decided that "fish" should refer only to certain gilled, finned vertebrates. Much hilarity ensued.
The cuttlefish is not a fish but a cephalopod (the same class that octopodes and squids belong to).
"Walrus" is derived from the Norse name, which translates as "horse-whale"
Similarly, "Porpoise" means "pig fish"
Some Roman texts referred to crocodiles as "Egyptian fish"
As an aside, the thinking that anything that lived in water was a "fish" proved to be a convenient loophole during Lent. You couldn't eat chicken—but you could eat beavers. Some populations of turtles have even been endangered or wiped out by demand driven by this thinking. On the other hand, some South American people (South American natives ate capybaras and caimans, but not fish) are only alive because of it.
In a strange double-take on this trope, the Patagonian Toothfish is a sort of bass. It is also extremely tasty and served in the finest restaurants, but as a "Toothfish" sounds as tasty as deep fried molars tempura, the fish is instead sold as Chilean Sea Bass. The fish is in so high demand many fear it may wind up driven to near extinction through overfishing.
The Hippopotamus has received the same treatment that sea animals have. Its name is actually Greek for river horse. This extends to other languages as well: in Dutch and German, it's called Nijlpaard and Nilpferd respectively, both of which mean "Nile horse." In Hebrew; it's Soos Ye'Or, also meaning Nile Horse (Soos: Horse, Ye'Or: Biblical name of the Nile), although the word hipopotam seems to be much more common. It extends to Mandarin Chinese as well, with the term for hippopotamus being "河马" (hémǎ), literally river-horse.
Electric eels aren't even true eels, they are members of a group of electrical fish that includes the knife fish and the ghost fish.
Insects get their share of this, too:
"Bug" actually means "creepy-crawly", it's related to "bugaboo" and possibly to the Slavic words for "god" (gods can be scary); it can be applied not only to insects but to any arthropod (lobsters and crawfish, both, are sometimes called "mudbugs", and they're crustaceans, as are pillbugs). Scientists restrict "bug" to mean insects of the order Hemiptera, but technical jargon is not normative for common speech, any more than the grammar of Latin is normative for English.
Fireflies aren't actually flies, but beetles. The German name for them, Glühwürmchen, isn't better. It means "glowing worms".
"Glowworm" is a common name for the larval form of many species of fireflies in English as well. The ladybug is more properly known in entomological circles as the ladybird beetle—from "ladybird," which is the older term (ladybug is the Americanized variety). They got their name from the Lady, as in the Virgin Mary, because she used to be portrayed wearing a scarlet cloak (the spots on the beetle are said to represent her seven joys and seven sorrows). Other language names for the ladybug/ladybeetle/ladybird make the connection more obvious: in German they're called Marienkäfer (Mary-beetle). It's even weirder in Hebrew: Coming from an earlier Yiddish name (and earlier than that, various Central European nicknames) they are called Parot Moshe Rabenu after the Prophet Moses - lit. "Our Master Moses' Cows". Another common Yiddish name for them was "Moses' Horses".
Several dialects of French, notably Cajun, call ladybugs "vaches du Bon Dieu", "the Good Lord's cows." Similarly mantises are "chevaux de diable", "the devil's horses".
In Polish the ladybug's official name is biedronka, but in some regions it's still called Boża krówka ("the Lord's cow"), especially by elderly people. Even in areas where it's called biedronka, there's a strong religious connotation, and there is even a nursery rhyme which goes: "Biedroneczko, leć do Nieba, przynieś mi kawałek chleba" ("Ladybug, fly to Heaven and bring me some bread") - it's usually spoken by little kids who set free a ladybug they've caught.
In Russian, a ladybug is also "the Lord's cow" (Bozhya Korovka), and an analogue of the above rhyme exists.
In Danish they're called Mariehøner which is Mary-hen.
Camel spiders and wind scorpions are neither spiders nor scorpions. (They're Eldritch Abominations.) Actually, they're "solifugids", a unique group of arthropods that somehow got labeled with the names of more common arachnids.
Bald-faced hornets (Dolichovespula maculata} are more closely related to yellow jackets (Vespula species) than to old-world or true hornets (Vespa spp.). Yellow jackets, especially the queens, are also often called "ground hornets".
This just doesn't happen to animals, but to plants as well. Just as "fish" used to mean "anything that lives in the sea," "apple" used to be a generic term for any fruit.
Tomatoes suffer from quite a bit of disassociative categorizing. Botanically, they are fruits, but culinarily they are considered vegetables (and thus everyone assumes they are veggies). This has led to some legal hilarity; the Supreme Court of the United States, during the 1893 case Nix v. Hedden, decided that tomatoes should be classified as vegetables under customs regulations; the court unanimously agreed that the Tariff Act of 1883 used common, not botanical, meanings for "fruit" and "vegetable." The case has been cited as precedent for defining tomatoes as vegetables ever since, which is why it's the official state vegetable of several American states.
Tomatoes were once called "love apples". The French name for them, pomme d'amour, is thought to be a corruption either of pomi di Mori (Moor's apple) or pomodoro, the later because the first tomatoes to hit Europe may have been orange in color.
Potatoes have been likened to apples in several languages. The textbook French name for the potato is pomme de terre—"apple of (the) earth", although patate is also used. The Dutch call them Aardappel, which literally translates to "Earth Apple." The Hebrew name for potatoes, Tapu'Akh Adama, also means "apple of (the) earth" (Tapu'Akh = Apple, Adama = Earth/Soil). This is also true for the German word Erdapfel, although Kartoffel is far more common—but the German term for French fries is the French loanwordPommes Frites, literally meaning "fried apples."
The French also have the "patate douce" (sweet potatoe). Sometimes, some French say only the "patate douce" can be called patate. Nobody ever agrees.
It gets more complicated: In America, at least, the "sweet potato" (I. batatas) is also called a "yam". The problem is that a yam is a completely different vegetable (Dioscorea spp.) that 'resembles' the sweet potato only in that it is an edible root; sweet potatoes are generally about six inches long, thin-skinned, and related to morning glories. Yams are tough-skinned, up to 8 feet long, can weigh 100+ pounds, and are related to lianas (those things Tarzan swung on). The sweet potato is also a common term for the ocarina, which is a musical instrument and not edible (except in the context of some P.D.Q Bach works).
Presumably the sweet potato (New World) being called a yam (Old World) is because most agricultural workers in (Anglophone) America were African slaves, who applied this trope to the local root vegetables (yams are a major staple crop in much of Africa, including many places the slaves came from).
Another Hebrew take on the apple is the "golden apple", i.e. the orange ("Tapuz", which is an abbreviation for "Tapuach Zahav"). It's a fairly recent addition to the language, and this fruit apparently had no previous Hebrew name whatsoever (foreign names were used).
The English word "corn" used to refer to any grain, such as wheat or barley. When English speakers reached the New World and first saw the yellow grain that grows on a cob, they called it "maize", based on a native name for it, but at some point started calling it "sweet corn" instead. North American Anglophones, however, called it "Indian corn", then shortened this to "corn"; "sweet corn" refers only to certain varieties. The rest of the world still calls it "maize".
The confusion between different meanings of the word "corn" leads to much hilarity when those unfamiliar with it translate English literature into, say, Korean. Fields of maize appear in medieval England and children become unreasonably tall.
This is also true to French-speaking North Americans (especially French Canadians) - though "maïs" (French for "maize") is generally understood, French Canadians generally refer to it as "blé d'inde", wheat from India (or, "Indian Corn").
Grapefruits are a citrus fruit, not an actual grape. They got their name because they grow in clusters, which look like bunches of grapes—but "grapefruit" isn't their original name. They were originally known as "shaddock" or "shattuck" until the 19th century.
Shaddock is also a name for the pummelo, the grapefruit's larger cousin.
The word "pineapple" was originally a word for what we now call a pine cone. Pine trees are not related to apple trees. The word was then applied to the fruit now known by that name, since it resembled a pine cone. Pineapple plants are not related to pine trees. Finally, the word "pineapple" for a pine cone fell out of use, being used exclusively for the fruit. Pineapple plants aren't related to apple trees, either.
Kiwifruit used to be called "Chinese gooseberries." They were deliberately renamed to "kiwifruit" for marketing reasons, since they resembled the eponymous flightless bird — well, insofar as both are small, brown, off-round, and furry-looking.
Kiwifruit itself in Chinese is usually given a weird assortment of names, currently being known as a Macaque Peach, despite the fruit looking nothing like a peach (or a macaque!). It's also called a pear in some versions
Along the same lines, the cape gooseberry is not related to actual gooseberries, or any other plant (such as the kiwifruit) that is sometimes referred to as a gooseberry. They're also sometimes called "ground cherries," due to their sweetness and tart undertones, but they're also not related to any variety of cherry. They're actually closely related to tomatillos and tomatoes.
Neither water hemlock nor poison hemlock (both "hemlocks" are poisonous) are related to hemlock trees (nor very closely to each other).
The name "oregano" has been given to several different species on the basis of similar flavor and aroma; e.g., Mexican oregano and Cuban oregano are completely different plants. Also, true oregano and majoram get mixed up in several languages, with either being named after the other.
Even viruses get this treatment. The illness that is sometimes known as "the stomach flu" or "the 24-hour flu" is not even remotely the same virus as the one you get immunized against every year. The stomach flu, or gastroenteritis, affects the stomach and digestive tract. The flu, or influenza, is an upper respiratory infection.
Nutrias are neither rats nor beavers, they are in their own separate family. Muskrats and water rats aren't true rats either.
"Rat" and "mouse" are terms erroneously applied to dozens if not hundreds of species of non-murid rodent, from packrats and mole rats (two for one, as they're not moles either!) to dormice and kangaroo mice.
Bear in mind that the "nutria" in South America is a rodent, but it was named by the Spanish after the Eurasian otter.
The trees of the Pacific Coast called cedars (genera Thuja, Chamaecyparis, Calocedrus, etc.) are not related to the true cedars(genus Cedrus), which are native to the Mediterranean and Himalayan regions, although three of these species have been cultivated in America. The only things in common are that they both are conifers with aromatic wood.
Do a web search for a picture of a Sea Hare and decide for yourself if it looks anything like a relative of the bunny rabbit.
Since horses died out in the Americas at the end of the last Ice Age, Native Americans often made use of this trope when Europeans came riding the beasts thousands of years later:
The Blackfeet called horses "big dogs".
To the Aztecs, they were "Castilian stags".
After conquering the Aztecs, Cortés made a (friendly) stop in the Mayan city of Noh-Petén/Tayasal while on a expedition to Honduras, where he left a horse that had been injured and couldn't keep the march. A century later, two missionaries visited the city and found that the natives worshiped an unmistakable statue of a horse they named "the fulgurant tapir" (hilariously one of the most accurate terms, since tapirs and horses are actually related, and horses are "fulgurant" when compared to tapirs).
A double example happens in the 1570 Inca account of the conquest of Peru by Titu Cusi Yupanqui, who says that when the Incas first saw horses they though of them as "big sheep in silver shoes". By "sheep" he actually means llamas, who had been called "Peruvian sheep" by the Spanish (the account is written in Spanish because the Incas didn't have an alphabet of their own).
The Dutch language has many examples of these:
A seal is called a "zeehond" (literally: "sea dog").
A lamantine is called a "zeekoe" (literally: "sea cow")
A hippopotamus is called a "nijlpaard" (literally: "Nile horse")
A whale is called a "walvis", despite not being a fish at all.
A harbour porpoise is called a "bruinvis" (literally: "brown fish"), despite not being a fish, nor always "brown".