The unicorn is a legendary creature shaped like a horse but with a single - usually spiral - horn growing out of its forehead. Some accounts describe it as having the body of a deer and the head of a lion.
The unicorn was a common symbol during the Indus Valley Civilisation, appearing on many seals. It may have symbolised a powerful group.
Ancient Greek accounts of unicorns locate their habitat in India. The unicorn did not appear in Greek mythology, but as an actual - albeit exotic - beast.
In medieval times, entrepreneurs would occasionally manufacture a unicorn by surgery on a goat kid: they would remove one horn bud and relocate the other to the centre of the forehead. (This technique continued to as recently as the 20th century, for circus displays.) Narwhal tusks, however, provided the main source of "unicorn" horns.
In popular belief, unicorn horns could neutralize poisons. Therefore, people who feared poisoning sometimes drank from goblets made of "unicorn horn". Alleged aphrodisiac qualities and other purported medicinal virtues also drove up the cost of "unicorn" products such as milk, hide and offal.
The unicorn also served as a common symbol of purity and of Jesus Christ. The traditional method of hunting unicorns involved entrapment by a virgin. This is believed to stem from the method of trapping Rhinos in Africa. A female monkey would be taken to where the Rhinos were and would dance for them. The Rhinos would become mesmerised by the antics of the monkey and would thus be an easier target for the hunters.
The unicorn also functions as a national symbol of Scotland and appears on many British symbols, notably as a supporter of coats of arms.
In fantasy fiction, a unicorn often has magical qualities or powers.
The constellation Monoceros represents a unicorn.