The unicorn is a legendary animal that has been described as a beast with a large, pointed, spiraling horn projecting from its forehead. The unicorn was depicted in ancient seals of the Indus Valley Civilization and was mentioned by the ancient Greeks in accounts of natural history by various writers, including Ctesias, Strabo, Pliny the Younger, and Aelian.The Bible also describes an animal, the re'em, which some translations have erroneously rendered with the word unicorn.
In European folklore, the unicorn is often described or seen in pictures as a white horse-like or goat-like animal with a long horn and cloven hooves. In the encyclopedias its horn was said to have the power to render poisoned water potable and to heal sickness. In medieval and Renaissance times, the horn of the narwhal was sometimes sold as unicorn horn.
There could be many possible origins of a unicorn. Hunts for an actual unicorn as the basis of the unicorn myth, accepting the conception of writers in Antiquity that it really existed somewhere at the edge of the known earth, have added a further layer of mythologizing about the unicorn. These have taken various forms, interpreted in a scientific, rather than a wonder-filled manner, to accord with modern perceptions of reality.