Unicorn
This article will focus primarily on the medieval unicorn - people can feel free to add onto this article with anything else they feel would be necissary.
Overview
The unicorn is a mythiological creature commonly said to be a horse with a single, spiraling horn growing from it's forehead - thus uni-, meaning "one", and cornus, meanin "horn". Also known as the Monocerous (mono-" again meaning "one" and cerous menaing "horn").
However, the unicorn's actual appearance is quite varied. It is said to resemble a kid, an ox, a wild ass, or a deer. It is even said to resemble a hodgepodge of these animals, with the feet of a goat or deer, the body of a wild ass, and the tail of a lion. One thing is in common with all of these descriptions, however - the unicorn strongly resembles either an equus or an ungulate, and all have the long, magical horn known as the alicorn.