The first true bestiaries—exhaustive anthologies of the natural world—appeared in Ancient Greece. Originally, they were just a means of cataloguing and describing all known animals and plants (both real and mythical), and in particular those that had curative or otherwise noteworthy uses. But by the Medieval period, when bestiaries became hugely popular, these descriptions had become overtly religious and allegorical, with many creatures listed as having miraculous powers, or depicted as symbols of redemption, salvation, and rebirth: the humble pelican, for instance, was once said to have the ability to bring its dead offspring back to life by piercing its side and feeding them its own blood (according to one 13th century French scholar at least).
One thing all bestiaries had in common, however, was that they mixed fact with fiction. Genuine accounts of real-life animals, birds, insects, plants, and gemstones were listed alongside ludicrous descriptions of bizarre, legendary animals—from magical birds that produced light-emitting feathers to bulls that could spray furlong-long jets of scalding poop. Twenty fantastic beasts precisely like these are listed here.
According to the Roman naturalist and scholar Pliny the Elder, the bonnacon or bonasus was a bull-like creature that lived in the ancient kingdom of Paeonia (modern-day Macedonia) that had a horse’s mane and backward-facing horns that were curled in on themselves in such a way that they were essentially useless. Instead, in order to defend itself, the bonnacon was supposedly able to spray flaming hot dung out of its behind, leaving a stinking trail as long as 300 feet behind it. Anyone who was unlucky enough to touch or be struck by the dung was burned as if they’d touched fire—although some descriptions claim that the dung actually set fire to anything it touched.
The echeneis, or “sucking-fish,” was described in a number of ancient bestiaries as a fish that, although small in size, was so strong that if it were to latch its flattened head onto the hull of a ship, it could hold it in place like an anchor. Some accounts claim the echeneis had feet, but according to Aristotle, this was incorrect—their fins just looked like feet. Pliny the Elder, meanwhile, claimed that it had the power to “hinder litigations in court,” stop “fluxes of the womb in pregnant women” (thereby “holding back the offspring till the time of birth”), and was even responsible for Marc Antony’s defeat at the Battle of Actium in 31 BCE. Although Pliny might have been exaggerating things a little, the legendary echeneis was nevertheless based on a real-life sea creature: the remora, or “sharksucker,” a bizarre eel-like fish whose dorsal fin has been modified into a flat suction pad, allowing it to attach itself to the undersides of larger marine animals.
The parandrus was an ox-sized, hoofed animal of Ethiopia with a stag’s head, large branching horns, and long shaggy brown fur. It didn’t stay brown for long, however, as the parandrus could apparently change the color of its fur to blend in with its environment.
The hercinia was a legendary bird believed to inhabit the Hercynian Forest surrounding the River Rhine in southern Germany. What made the hercinia special was its glowing plumage, which produced so much light that anyone walking through the forest at night could use the bird or one of its feathers as a lantern.
The scitalis was an iridescent serpent whose scales glistened so amazingly that they would stun anyone or anything that saw it, thereby stopping them in their tracks so that they could be caught or bitten. All that iridescence came with a cost, however: the scitalis often became so hot that its skin would burn, forcing it to shed its skin even in winter when all other snakes are hibernating.
A popular image in heraldry, the alerion was said to be the king of all birds. Fire-colored and larger than an eagle, its wings were as sharp as razors. Supposedly, only one pair of alerions were ever alive at one time: When she was 60 years old, the female would lay two eggs that would then take 60 days to hatch, whereupon the parents would immediately fly far out to sea to drown themselves. The two chicks would then be reared by all the other birds until they reached adulthood.
Cynocephalus literally means “dog head,” and according to some ancient writers was the name of a species of dog-faced apes native to Ethiopia. According to Aesop, they always give birth to twins, one of which the mother was always destined to love and the other to hate. The apes are such affectionate mothers, however, that they could hug their babies to death if they were not careful.
The caladrius was a pure-white bird said only to live in kings’ houses. Among its many bizarre qualities, the caladrius supposedly had the ability to diagnose (and cure) illness: If it were to look at you while you were unwell, then you could rest assured that you would eventually recover (the bird takes the sickness into itself and flies up to the sun, where the sickness gets burned off); but if it looked away, you were destined to die of your illness. And as if that weren’t useful enough for medieval physicians, the caladrius’s poop was also said to be able to cure cataracts.
Ancient descriptions of the leontophone ranged from a boar-like mammal to a tiny worm or serpent, but one thing was always mentioned: The leontophone was lethally poisonous to lions. If a lion ever caught one, it would tear it apart with its claws rather than its mouth, because if it ate or was bitten by a leontophone, it would die instantly. According to one 12th century bestiary, in order to kill a lion, a leontophone should first be caught and killed, then burned and its ashes sprinkled on a piece of meat. The meat should then be placed at a crossroads as bait for the lion, which would die immediately on eating it.
The jaculus, or “javelin-snake,” was a flying viper that lived in the tops of trees and killed its prey by falling onto it, or by firing itself through the air “like a missile from a catapult,” according to Pliny.
The corocotta or leucrota was the legendary offspring of a hyena and a lioness. The size of an ass with a horse-like head, the back legs of a stag, and hooved feet, the corocotta had a mouth that stretched from ear to ear and, according to Pliny, “an unbroken ridge of bone in each jaw, forming a continuous tooth without any gum.” As if that weren’t strange enough, they also apparently had the ability to mimic people’s voices.
Unlike the real-life sawfish’s bizarre saw-shaped face, the legendary sawfish took its name from a saw-toothed crest that ran along the length of its back, which it supposedly used to cut into the hulls of ships by swimming underneath them, so that it could drown and then devour the crew. When it wasn’t busy doing that, the sawfish used its enormous wings to fly clear of the sea and race ships—although it could only sustain itself for a distance of around 30-40 furlongs (3¾-5 miles/6-8km), after which it would plunge back beneath the waves.
If a centaur had the head and torso of a man with the body and legs of a horse, then the onocentaur was its less impressive relative: It had the head and torso of a man, and the body and legs of a donkey.
Native to Ethiopia, the yale was described by Pliny as the size of a hippo, black or tawny-brown in color, with the tail of an elephant and two coiled horns. Its skin was so thick that it couldn’t be wounded, and when two males fought, they would hold one horn forward and the other backward depending on their needs. It was probably inspired by early descriptions of the African water buffalo.
In English, a wether is a castrated ram or goat, but in the medieval bestiaries it was the name of a specific type of sheep that was much larger and stronger than all others. The Latin name for the wether was vervix, which led the 7th century Spanish scholar Isidore of Seville to theorize that the wether’s head was naturally infested with worms (the Latin for which was vermis) and when the worms started itching, they scratched the itch by butting their heads together.
The allocamelus (literally “other-camel”) had the head of a donkey and the body of a camel, leading the 17th-century English writer Edward Topsell to believe it to be the offspring of a camel and a mule. In fact, it was probably based on early descriptions of a llama or an alpaca.
The Ethiopian catoblepas was a described as a sluggish, cow-like creature with a head so large and heavy that it couldn’t look upward (catoblepas means “downwards-looking” in Greek), while one smell of its breath or a glance from its bloodshot eyes could kill a man immediately. Despite that fairly unflattering description, it’s thought that the catoblepas was based on the African wildebeest.
A serpent that’s so exceptionally flexible that it appears not to have a spine, the cerastes also had two or four ram-like horns on its head that it could move independently. To hunt, it buried its body in the sand or earth, leaving just its horns exposed above the ground, which it waggled around to attract its prey. (At least, that’s according to Leonardo da Vinci.) The myth of the cerastes is probably based on the north African horned viper—whose Latin name, appropriately enough, is now Cerastes cerastes.
The muscaliet had the body of a hare, the tail of a squirrel, a mole’s nose, and a weasel’s ears. It nested in hollows beneath the roots of trees, but produced so much heat that it would dry the tree out from the bottom upwards and kill it.
The sphinx-like manticore had the head of a person, with the body of a red lion, a scorpion’s stinger, a voice like a whistle, and three rows of comb-like teeth. The lampago, meanwhile, was a tiger with the face of a man, and a satyral had a lion’s body, an antelope’s horns, and the head of an old man. All three were once popular heraldic images and often appeared on medieval coats of arms.