In the 1920s, archaeologists in South Asia unearthed remnants of the Indus Valley civilization. It was a thriving, advanced culture in present-day Pakistan and India that disappeared around 1900 B.C.E. Among its artifacts are seal stones, tablets inscribed with symbols and drawings — the "Indus script," which has yet to be cracked.
But at least one etching is easily identified: a long, four-legged animal with a single, spiraled horn protruding from its forehead.
The Indus unicorn isn't the creature of modern fairy tales. It looks a lot like a single-horned bull (some suggest it's actually a regular, two-horned bull in profile). The horn is usually curved to some degree, and the hooves and tail are bovine. The carvings show folds of skin along the face and throat, and a snout that is sometimes short and square, other times almost llama-like.
The Hair of a Buffalo
"The Last Unicorn" it is not. But neither is it the least graceful unicorn in history. Italian explorer Marco Polo in 1300 A.D. described one with the head of a wild boar, the hair of a buffalo, the feet of an elephant and a long, black horn.
Few early versions of the unicorn resemble the luminous, horse-like beings of modern myth. Descriptions of the creature go back thousands of years in folklore, both Asian and European, as well as in naturalist catalogs and, by some Christian translations, the Bible. All of these unicorns have a single horn, four legs and a tail — and that's about it for universal characteristics. (Actually, one Indian myth tells of a unicorn boy, the son of a human and a one-horned antelope. But that's an outlier.)
The unicorn myth may have originated in sightings or reports of exotic animals like rhinoceroses and narwhals, or of typically two-horned animals that were missing one. The American Museum of Natural History hypothesizes that Marco Polo's unicorn was a Sumatran rhinoceros, native to Southeast Asia. Roman naturalist Pliny the Elder, who described unicorns around 77 A.D., may have been describing the Indian rhinoceros.
The Head of a Dragon
Early Asian unicorns varied widely in physical appearance. In Chinese and Japanese folklore, the unicorn often has a scaly or multicolored coat, a flesh-covered horn (or horns), the body of a deer and the tail of an ox. The head may be dragon-like. In some myths, it is a harmless, solitary creature whose presence portends good. In others, it portends death.
The Japanese unicorn has the mystical ability to detect evildoers — and upon detection, drives its horn through their hearts.
In "Unicorns: The Myths, Legends, & Lore," Skye Alexander describes a Persian unicorn with three hooves on each leg. Varying legends paint it as a shapeshifter, a ferocious warrior resembling a rhinoceros or a peaceful, deer-like creature. It can purify water by dipping its horn into the liquid — at which point all females in the vicinity become pregnant.
Versions of European unicorns have a similar purification ability. Their horns can detect and counteract poisons by contact (though no resulting pregnancies are reported here). The horn can also heal and protect from disease.
The Horn of a Narwhal
Beliefs like this led to a strong European market for unicorn horns, and in the Middle Ages opportunistic sailors started selling narwhal tusks as unicorn horns. Before that, says the American Museum of Natural History, European unicorns often had stubby and/or colored horns. After that, the horns were "long, white and spiraled."
Western unicorn mythology brings us somewhat closer to the modern myth. European unicorns often have white coats, a horse's body, the hooves and beard of a goat and the tail of a lion. These unicorns are nearly impossible to catch, a trait credited to strength or general elusiveness. But they do have a weakness.
A virgin woman can lure the European unicorn into the open. She seems to entrance the creature, who may lay its head in her lap — by some accounts suckle at her breast — leaving itself vulnerable to capture by hunters waiting out of sight.
This association with the virgin, along with reported biblical mentions and the abilities to heal and counteract poison, led the medieval Christian church to cast the unicorn as a Christ figure. The creature thus increasingly came to represent purity and nobility, likely contributing to modern representations of the unicorn as benevolent, regal, graceful and white.
How it became the sparkly, smiling creature of popular culture, seen in the works of Lisa Frank, the My Little Pony empire and farting-rainbows memes is not entirely clear, but it probably has to do with commercial value. Kids are drawn to unicorns. Their parents buy them unicorns. Single-horned chimeras that impale bad people with their horns likely wouldn't fly in the 6-year-old set.
Where the Indus Valley unicorn fits into known unicorn legend remains a mystery. That its image appears on more than a thousand seals recovered by archaeologists suggests it was highly valued. It may have been sacred. It may even have been real. The Indus unicorn will keep its secrets until science finds the key to the ancient code.