There is perhaps no limit to the human imagination to come up with new ideas, but it is very likely that unicorns are based on accounts of other, very real horned animals like the rhinoceros. The medieval writers themselves would have probably never seen such animals with their own eyes, but they might have heard tales of them. And how would one describe such an animal? One horn, body like a horse, tail like a lion - that sounds a lot like descriptions of unicorns. Artists of the time would have come up with their own idealized pictures based on the few details they had second (or even third) hand and, voilá, there's a painting of a cute little unicorn prancing around in some meadow.

Hate to be the one who pokes the rusty nail into the fine well-oiled clockwork, but the medieval template for this gracious and magnificent beast was...the goat. I´m speaking strictly of the westren unicorn, the animal we recognize today as the white one-horned horse, Chinese unicorns were quite different, bigger, more saurian-like, scales and all (Centrosaurus anyone?) Medieval descriptions of unicorns however tend to point in the same direction, chief among them are the famous ´unicorn tapestries´, woven by an unknown master-weaver 1495-1505. The creature in these seven tapestries is undoubtedly a goat, it´s slender, white, with a narrow jaw, cloven hooves and a beard. It even has hair on it´s legs, a trait found in horses, but much more common in goats. The only real difference between this fabled creature and a true goat is the horn and the weird tail. The horn can be explaned with mutation or manipulation. A genetic mutation that causes the two horns to interlock and grow together is highly plausible, and has been known to happen in various horned animals, and manipulation on horn-buttons on kids (baby goats),albeit cruel, have been documented as late as the 20th century (The Living Unicorn, 1985). The tail is trickier, though I belive it was ment to resemble a lions-tail to give the creature an added feeling of ferocity, or to simply differentiate it from all other known creatures. Medieval writers often describe unicorns as cloven-hooved animals with a fierce, independant nature, all synonymous with the wild goat, the unicorn didn´t become horse-like until the 18th century romantics transformed it, probably because they thought the horse was a nobler creature.