A unicorn is a mythological creature. Strong, wild, and it was impossible to tame by man. A Roman naturalist records it as "a very ferocious beast, similar in the rest of its body to a horse, with the head of a deer, the feet of an elephant, the tail of a boar, a deep, bellowing voice, and a single white horn, two cubits in length, standing out in the middle of its forehead."
Both hunters and zoologists have generally disbelieved the existence of the unicorn. Yet there are animals bearing on their heads a bony protuberance more or less like a horn, which may have given rise to the story. The rhinoceros horn, as it is called, is such a protuberance, though it does not exceed a few inches in height, and is far from agreeing with the descriptions of the horn of the unicorn.
The nearest approach to a horn in the middle of the forehead is exhibited in the bony protuberance on the forehead of the giraffe; but this also is short and blunt, and is not the only horn of the animal, but a third horn, standing in front of the two others.
It was traditionally believed that a virgin who was naked sitting beneath a tree could only catch the delicate unicorn. The unicorn, who craves purity, would be irresistably drawn to the girl and lie down with his head in her lap. While it slept, the hunter could capture it. If, however, the girl was merely pretending to be a virgin, the unicorn would tear her apart.
Throughout the stories of the unicorn, its horn, the alicorn, is said to have great medicinal powers. In Ctesias’ writings, the dust filed from the horn was supposed to protect against deadly diseases if mixed into a potion. Or, if one drank from the horn, they would be protected against any poison. Often, a narwhale tusk was sold as an alicorn, and it was often ground up and used for its magical properties.