Unicorn

The unicorn is a legendary creature like a horse, but with a slender, usually spiral, horn growing out of its forehead. The popular image of the unicorn is that of a white horse differing only in the horn.
In medieval lore, the spiraled horn of the unicorns was called the alicorn, and was thought to neutralize poisons. In popular mythology, unicorns were hunted for their horns, which were said to protect one against diseases, or, if made into a cup, would protect on eform any poison that might have been added to one's drink. This belief is derived from Ctesias' reports on the unicorn in India, where it was used by the rulers of that place for anti-toxin purposes so as to avoid assassination.

People sold what they purported to be unicorn horns at this time, but were actually selling narwall horns (narwalls are whales with large, horn-like tusks that swim in cold water.)

Traditionally, the unicorn had a billy-goat beard, a lion's tail, and choven hoofs. Ironically, this perception was more realistic, as only cloven-hoofed animals have horns. Unicorns were once thought of as nasty, easily provoked creatures, unlike the gentle perception we have of them today. They were thought to have deep, bellowing voices. As Ctesias, the ancient Greek physician, said:
"The unicorn was native to India, the size of a donkey, with a burgundy head and white body; it had blue eyes, a single horn that was bright red at the top, black in the middle, and white at the bottom; the horn was also eighteen inches long."

A widespread legend is that, when Noah gathered two of every kind of animal, he neglected to gather the unicorns, which is why they do not exist today.

The first written reference in literature was in the 4th century B.C., when the greek doctor Ctesias in the service of the Persian king heard many tales from Indian travelers about creatures. Later writing them down, he described "wild asses as large as horses" that had white bodies, red heads and dark blue eyes, and "a horn on the forehead, which is about a foot and a half in length." He also said that the horns were multicolored, and that the animals were so swift and powerful that "no creature, neither the horse or any other, could overtake it." They called it monokeros "one-horned".