In Real Life, vertebrates have at most four functional limbs — legs, arms (which anatomically are really modified forelegs), or wings (which are modified arms) — and one tail. If it has more than that, like arthropods (insects, spiders, centipedes, etc), it's not a vertebrate. Some individuals have abnormal numbers due to injury or glitches during development, but additional limbs rarely function properly. Those with less, like snakes and whales, still evolved from four-limbed animals.
There's nothing intrinsically wrong with six or more legs — it's just that current large land animals originated from a species with a four limb body plan, and adding more requires all sorts of complicated skeleton and muscle changes that are much more complex than just making the ones the organism already has a little better. Or, if they're weighing the critter down... take them out. Just look at whales for a demo. This apparently happens a lot — evidence suggests that when the first fish crawled out of the water, it did so on seven-toed feet. (For more info on the topic, try the other wiki)
Of course the fact that there's one standard land vertebrate body plan doesn't stop fiction writers from subverting nature's tropes. This trope may be exactly as old as dirt, for a number of documentaries have suggested that many tales of fantastic creatures could have been inspired by early humans encountering bones of prehistoric creatures and misinterpreting the evidence. For reasons that should be obvious, in modern writing, vertebrates with five or more limbs is primarily a Speculative Fiction trope. They're often very useful in said fiction, in combat or for grabbing.
Sometimes justified because A Wizard Did It or because there's no obvious reason why aliens would always have exactly four limbs, but trying to determine the internal anatomy of such creatures may lead to Fridge Logic. While in most cases authors Hand Wave such things, it doesn't stop others from trying.
Note: as the subtropes get filled out with three or more examples, they can be TLP'd and moved into separate subtropes.
Contrast Four-Legged Insect, which provides examples of invertebrates with fewer limbs than in real life.
- Multi-Armed and Dangerous
- Multi-Armed Multitasking
- Our Centaurs Are Different
- Spider Limbs
- Winged Humanoid
Multilegged Land VertebrateA creature, almost always a fur-covered mammal that normally has four legs, has six or more fully-formed legs for no other obvious reason than the Rule of Cool.
- The Norse God, Odin had an eight-legged horse named Sleipnir. Which was born from Loki (shape-shifted into a mare at the time) and a giant's stallion. The extra legs let it run faster.
- Basilisks, depending on the depiction. While many have two chicken legs and two either bat-lizard or bird wings, and some are just snake-like, several depictions have four lizard and/or chicken feet in addition to the wings, or no wings but more than four legs, often of the lizard variety.
- Asian dragons, being usually associated with rivers or water, almost never have wings but can have four or more legs (usually depending on how long/powerful the dragon is). For an example, see the river spirit in Spirited Away. More rarely, Western dragons can also look like this.
- The true form of Shirogane from Ayakashi Triangle is a Great White Feline with six legs (four forelegs, two hind legs). His Sleep-Mode Size is simply quadrupedal.
- The land vertebrates of A Centaur's Life evolved from a common hexapod ancestor but turned out quite close to ours, with many species in common but six-limbed: six legged cows, dogs and horses, and about six main human sub-species, including some with wings and two centauroid forms, one extinct.
- The Catbus from My Neighbor Totoro and the Kittenbus from the OVA of the same universe.
- The Pokémon Giratina has six legs when in its Altered-Form.
- One of the Eight Kings, the Deer King, is a continent sized deer with 7 pair of legs in Toriko.
- Most of the Pandoran wildlife in Avatar has six limbs: two pairs of forelimbs and one of hind. The Na'vi do not; this is explained in-universe by their evolution from the monkey-like creatures Jake sees on his first trip out which also have six limbs, but the forelimbs on each side are joined at the elbow — so, two total upper arms and four total lower arms.
- Justified with Stitch from Lilo & Stitch: he is not only an alien, he's a genetic experiment as well. Also, most of the time he keeps his extra arms hidden so muggles mistake him for a dog.
- Book of Imaginary Beings: Borges records a Siberian myth according to which antelopes once had six legs. This made them far too fast for humans to catch, so a divine huntsman cut off the hindmost pair to make them easier quarries.
- Honor Harrington:
- Treecats have six legs, as do most other native land vertebrates from Sphinx, their homeworld, including the Hexapuma and Sphinx Chipmunk.
- Ditto the native vertabrates of the planet Safehold from the series of the same name.
- Also played straight with the native Medusans, a primitive sentient race on the planet Medusa of the Basilisk system. They have three arms and three legs (six total).
- Jack Vance's Planet of Adventure features six legged beasts of burden.
- On Gor one of the most common animals is the sleen, often described as looking like a furred snake or lizard, which has six legs.
- Edgar Rice Burroughs' Barsoom novels had:
- 6 legs: the cat-like sorak and rat-like ulsio
- 10 legs: the elephant-like thoat, lion-like banth, and dog-like calot
- Apts: 2 arms and 4 legs
- Green Martians: 4 Arms and 2 legs
- The novel Glory Road by Robert A. Heinlein has horse-analogues with eight legs, on an alien planet. They are used as draft animals.
- In Anne McCaffrey's Catteni series, there are "loo-cows" that have six legs in order to constantly pound the ground at night and keep the monsters that live underground at bay.
- Raymond E. Feist's The Riftwar Cycle had a planet where most large animals had six legs, due to taking a different evolutionary path from Earth.
- There's a six-legged cat, among other things, in The Dark Tower. These animals are called "muties", which is presumably slang for mutant. Later on it's revealed that they are indeed descended from mutated four-legged cats.
- Thallonian riding beasts in Star Trek: New Frontier. Quite possibly, all Thallonian vertebrates (the Thallonians themselves aren't native to Thallon, so their four-limbed humanoid shape doesn't have to fit in).
- Xandri Corelel: Every vertebrate on Karrckchak follows a hexapodal body plan, resulting in six-legged land animals, birds with four wings, and a creature that resembles a deer, except that its "antlers" can function as tentacles.
- Catwings stars four cats born with wings on their back.
- James P. Hogan's The Immortality Option (sequel to his better-regarded Code of the Lifemaker) presents the Borijans, a species of birdlike aliens from the planet Turle. What's interesting about these Bird People is that not only do they have six limbs (two legs, two arms, and a pair of non-functioning but socially important wings), all of the higher (vertebrate-equivalent) life on Turle follows the same general six-limbed body plan.
- Space Brat: The generally dog-like Poodnoobies have six legs.
- Rod Allbright Alien Adventures: Chiblings start off looking more like caterpillars, with several pairs of legs. When they reach the third stage (and split into two animals), one half undergoes a metamorphosis into a form that starts with just four legs, but grows a third pair later.
- On Paleo Planet, Jasper sees a group of rodents that resemble meerkats with four sets of legs.
- Alkalinians naturally have three sets of small legs, although high-ranking Alks have theirs amputated and replaced with a single robot arm.
- Bruce Coville's Book of...:
- Bruce Coville's Book of Monsters: The titular character of The Beast With a Thousand Teeth has six legs.
- Bruce Coville's Book of Aliens: The Kwarkissians in I, Earthling have six arms each.
- The Outer Limits (1995): In "Seeds of Destruction", DNA from TX-40, a genetically engineered strain of corn developed by a company called MacroSeed, crossed over to milkweed. The spread of the milkweed's pollen causes both people and animals in the small town of Hobson to develop tumours. In the case of a cat, a fifth leg grows from a tumour on its back. The cat is killed in the process.
- Star Frontiers had eight-legged land whales.
- Dungeons & Dragons has myriads. Some examples are:
- Displacer beasts have six legs. And two tentacles.
- The osquip is a rodent with between six and ten legs. In the Dragon magazine article/story "The Ecology of the Osquip", the wizard Buntleby, who has studied the creatures, speculates that their variable limb number may hold the key as to how the various multilegged, centauroid, and winged quadruped animals evolved.
- The planets Ungavorox and Grail in Fading Suns universe are known for their six-limber fauna.
- In Rocket Age some Martian animals, typically reptiles, have an extra set of limbs, despite most other animals including the Martians themselves only having four. This is possibly due to the large amount of genetic tampering the Ancient Martians engaged in.
- Talislanta has the Axe-Head, Durge, Erd, Rictus, and Urthrax, all with six legs.
- A parasite called Riberoia trematodes attacks tadpoles and burrows into their hind limb buds, damaging the growing limb so that upon metamorphosis the frog is redered crippled, is unable to escape predators and gets eaten, allowing it to move into its next host. While usually, afflicted frogs end up with stunted or missing limbs, some cases have been documented of them sprouting extra legs instead, as many as eight in certain cases.
- Scientists who were asked to imagine what an alien world would look like, and what sort of creatures might inhabit it, agreed that a six-limbed version of a common land vertebrate wouldn't be too unbelieveable.
- And not to mention Lakshmi Tatma, the 8-limbed girl.
- One of the three playable species in Achron is the Vecgir. They are a species that walk on two hind legs, stand about two meters tall and have two pairs of arms.
- The Warcraft games have basilisks, crocolisks, and diemetradons, all of which have six legs. However, the dragons in the game (who have 4 legs plus wings) did NOT evolve from these creatures. They are this trope because A Wizard Did It: the Titans transformed them from a type of creature now referred to as a proto-drake. Proto-drakes, surprisingly, avert this trope: their wings are connected to their forelegs. The explanation for the six-legged reptiles is probably that the Titans tested their transformation techniques on creatures they considered "lesser" than the proto-drakes, due to not being as eusocial and intelligent. The presence of diemetradons is a fairly reliable indicator that a Titan laboratory is somewhere nearby, or that someone has been messing with Titan tech. Crocolisks are one of the few creatures that appear on Draenor as well as Azeroth, a further indication that they are Titan creations. So again, probably A Wizard Did It.
- In the sequel to Crystal Quest, you learn that your Flying Saucer is piloted by a six-legged Space Cow.
- The Seekers, antagonists of Advent Rising, look somewhat like reptilian centaurs, with a two-armed humanoid torso supported by four legs. Interestingly, while their hind legs end in hooves, the forelegs have hands that are strong and dexterous enough to handle weapons; they are also seen to tuck the forelegs against their hind ones, standing upright at twice the size of any human.
- Galdon, the boss of DarkIce Mines in Star Fox Adventures is a six-limbed (four legs, two arms) carnivorous dinosaur with small tentacles on the sides of its head. It has a figure that falls somewhere between that of an insect and a centaur.
- Not that you can tell from their in-game portraits, but the Paranid in the X-Universe series have two sets of arms.
- The Necho Cat and Frootz Cat Dream Eaters in Kingdom Hearts 3D [Dream Drop Distance] have three pairs of legs. Oddly, they're the only examples of the trope among their kind.
- Inverted with the sligs of the Oddworld series. They're reptilian-looking creatures with arms and a torso, but no legs. Played straight with the Vykkers, who have seven limbs: four legs and three arms.
- The dogs in Wobbledogs can have more than four legs, and wings.
- In Champions of Far'aus, Faunza, in her monster form, resembles a six-legged fire salamander.
- Girl Genius:
- One of the Geisterdamen mounts in Girl Genius looks something like a horned, many eyed six legged giant salamander.
- Wasp weasels are weasel-derived creations of Sparks (Mad Scientists) with eight legs. They're supposed to fight small Hivers as well as detect infection, but it's not explained how the extra legs might help.
- Sierks and Ratamis in The Interstellar Tea House have six legs.
- Shaensigin is a semi wingless dragon looking Senet beast with six leg/arms. When she appeared in the story she was regrowing one pair so it was significantly smaller than her other sets.
- Sessine often looks like a creepy giant crow with six boobs, but she can spread her beak wide and push her bird-like head down like a coat to a slim red waist of a more humanoid torso with a pair of long thin arms and a set of strange bony appendages sprouting from her inner shoulders. She can only fly with her feathered skin pulled all the way up as her wings don't function well when she's got her feathered bits pulled back to her inner waist.
- Avatar: The Last Airbender has Appa the six-legged bison among others.
- In "Roller Coaster Dragon" from Dragon Tales, the dragon operating the concession stand has six arms. When Wheezie tells to hurry up because they need to get back in line to get on the roller coaster dragon, he asks if he looks like an octopus, saying that he only has six arms.
- In Tiny Planets, one of the alien protagonists has six limbs, which are usually legs although the front pair can also be used as arms.
Four Limbs Plus Wings (not including Winged Humanoids)A land vertebrate is shown with either four legs or arms and legs in addition to one or more wings or the remains of wings.
- The Boi-Vaquim from Brazilian Folklore is a winged bull from the Rio Grande do Sul state prairies with diamond eyes and golden, flaming horns.
- Western dragons are typically depicted as having four limbs and one pair of wings.
- Eastern dragons are sometimes presented as having as many wings as they do legs — pairs of both running all along both sides of their long serpentine bodies.
- Likewise, griffins also usually have four limbs and a pair of wings.
- Pegasus, the flying horse in Greek Myth, has four limbs and a pair of wings as well.
- The peryton from the Book of Imaginary Beings, a pegasus style animal only being a winged deer rather than a winged horse (and carnivorous, but that's another story). There's a recent tendency to portray it as a bird with a deer's head however, probably based on D&D.
- Semargl, a Slavic god, takes the form of a winged dog.
- Thai myth has a lot of fantastic mix-and-match critters, including numerous winged, six-limbed vertebrates. Among them are flying kirins, winged horses, a sort of griffin called kraisorn puksa, and even flying elephants.
- The titular God-monster in Q: The Winged Serpent has four legs and two wings.
- A man was driving on a country road, when he saw a chicken with four legs. The chicken started running alongside the car, easily keeping pace, then turned into a farm where there were several other four-legged chickens. He stopped the car to get a closer look at them, and was greeted by the farmer.
"Where did these chickens come from?" he asked.
"I breed them," the farmer replied, "Me, the wife, and our two kids all like chicken drumsticks. So I decided to breed a chicken with four legs, so we could all have one. And after years of hard work, I managed it!"
"That's amazing," said the man, "And what does it taste like?"
The farmer sighed. "If I ever catch one, I'll tell you."
- Hippogriffs, Thestrals, and Dragons in Harry Potter. Though dragons in the movie verse avert this. Their wings are part of their forelimbs.
- In Dragonriders of Pern, dragons are genetically engineered creatures descended from fire lizards, which also have four legs and wings but are much smaller.
- Also native to Pern are wherries, another fire-lizard-related species, which also have four legs and two wings.
- Tunnel snakes, who share a common ancestor with fire lizards and wherries, also have six limbs. In this case, instead of wings, they have three sets of legs; the front set adapted to digging. Six limbs could well be the norm for vertebrates on Pern, but thanks to Thread nearly sterilizing the planet every 250 years, there wasn't a lot of genetic diversity on the planet before humans came along and introduced Earth flora and fauna.
- Incidentally, supplemental material indicates that Pernese arthropods have four limbs.
- Kinshaya in the Star Trek Novel Verse. They have four legs and wings on their back. In an ancestral species, these were used for flying, but modern Kinshaya are too heavy and retain them for display purposes.
- In Robert E. Howard's Conan the Barbarian story "Queen of the Black Coast", when they spot the ruins, they also spot a winged ape. This ape is the last devolved member of the Winged Humanoid race that once had a thriving civilization in those ruins before environmental disasters killed most of them and mutated the rest. It's also still as intelligent as it is malevolent.
- The Borijans of James P. Hogan's The Immortality Option are an interesting take on this: their planet's vertebrates are six-limbed, but the intelligent species, the Borijans, are descended from birdlike creatures. So they have six limbs, but two are arms, two are legs, and two are vestigial wings.
- In The Magician's Nephew, a normal Earth horse winds up in Narnia and is given wings by Aslan.
- The Wonderful Wizard of Oz and various stories based on have the winged monkeys.
- The author talks about consciously averting this trope for the dragons in A Song of Ice and Fire.
GRRM: There are no actual dragons, to be sure. But there are bats, and there are birds, and once upon a time there were pterodactyls. Those are the models to use when designing a dragon. No beast in nature has four legs AND wings.
- Dungeons & Dragons has dragons, winged serpents (which aren't this trope because that's two limbs total), and many others. In 3.0 and 3.5 there were also numerous templates that could be added to a creature to give them wings, as well: half-celestial, half-fiendish, half-dragon (if the base creature was at least large size), and winged, just to name a few.
- Likewise Griffons and Hippogriffs follow the four limbs and two wings pattern, as do various types of Sphinxes.
- Evolve: The Kraken has four legs for walking and two limbs that act as both wings and bludgeoning weapons.
- Sonic the Hedgehog: Rouge is a white bat with separate arms and wings.
- Warcraft has many creatures with four legs and wings, such as dragons and gryphons.
- The World Ends with You has this among the noise forms. Kitanji rules this trope: He goes from no arms and legs as Anguis Cantus, to two four limbs a pair of wings and five heads as Draco Cantus.
- The Elder Scrolls: Morihaus, the Aedric demi-god who was sent to aid St. Alessia (as part of her Bargain with Heaven) in her war against the Ayleids, is described as a "winged man-bull" with functional wings.
- Dragon Quest II: Hargon's servant Pazuzu is a winged monkey.
- The Bean Team of Butterbean's Cafe have a winged flying cat named Cookie.
- Several characters in My Little Pony, being pegasi or dragons.
- And in the Friendship is Magic generation, griffons as well.
- She-Ra: Princess of Power character Imp possessed two arms, two legs, and two wings.
- Mantenna, a member of the Evil Horde, is an insectoid alien creature with two arms and four human-like legs which were positioned much like a spider.
- In Transformers, Transformers with aerial alternate modes tend to have four limbs alongside the wings of their alt-mode.
- Cats can grow "wings" from matted fur or medical conditions. They can't fly, obviously.
- Lizards of the genus Draco look like this, but their "wings" (which are only used for gliding) are actually modified ribs.
Vertebrate/Invertebrate MixWhen Mix-and-Match Critters include parts from invertebrates, the result can be a creature that appears to be a land vertebrate, but has more than four (and often much more than four) limbs.
- The Scar: The Cray have a humanoid upper body with two arms and a crayfishlike lower body with many jointed legs.
- The Little Mermaid (1989): Ursula, the main villainess, is half-octopus, and as such has a large number of tentacles sprouting from her waist instead of legs.
Other / Combos / Unsorted / Lost examples
- Bleach: Yammy has a released form of a centipede-centaur. Basically a giant human but with seven extra legs along a torso extending behind him.
- Angela's Pet Monster, Monsters, Inc. fanfiction: Randall's ex-girlfriend Sylvia Schneider is a wolf with four legs, two retractable arms, and a pair of wings.
- Pathfinder: It's common for a summoner's eidolon to end up with a large number of limbs, as increasing their number of attacks per round with extra arms, tails, tentacles, or heads is one of the easiest and most effective ways of boosting their power.
- City of Heroes allows the creation of player characters with wings, both organic and artificial.
- Charby the Vampirate: Demon King Samrick has four arms, two legs and a pair of wings.
- Grrl Power: The reason for the humanoid form being common among many non-Terran species is discussed by Dabbler during a press conference. Aside from the possible local benefits of six limbs instead of four, too many extra arms or legs (or eyes or...) or too much variation among the types of limbs is not efficient when it comes to survival, taking up resources while providing diminishing returns.note
- Serina: The gibbets and simiagibs have six limbs. They descended from the three-legged tribbets (terrestrial fish), but two fingers on each arm and two toes on the single hind limb became larger to aid in climbing trees, eventually developing their own fingers and becoming six functional limbs.
- In Real Life the prehistoric reptile Coelurosauravus, a relative of lizards that lived during the Permian Period, had four legs and two gliding "wings." Unlike today's gliding lizards, whose gliding membranes grow on spread-out ribs, Coelurosauravus's "wings" were an entirely unique set of bones not connected to its ribs. Their morphology suggests they evolved by ossification of connective tissues in the skin, though that's the sort of thing that almost never fossilized so it's difficult to confirm.