National Geographic:

Scotland associates the mythological animal with dominance and bravery. They are portrayed with a white horse head, body, and mane, a singular horn arising from the top of its forehead, and a gold chain that wraps around its powerful body.

Western civilizations believed in the existence of unicorns for thousands of yearsโ€”it was a symbol of purity, innocence, and power in Celtic mythology. The unicorn first appeared on the Scottish royal coat of arms in the 12th century by William I. In the late 15th century, Scottish coins featured an image of the unicorn, and it even appeared in artistic works during the Middle Ages, symbolizing the holiness of virgins, including the Virgin Mary. According to popular belief, only a virgin maiden had the ability to capture a unicorn because it was so enthralled by her virtue.