In Celtic mythology, the deer is a magical creature, able to move between the worlds. As in Eire many tales have humans transformed into deer. For example, St. Patrick was said to have transformed himself and his companions into deer in order to escape a trap laid by a pagan king. In the Welsh tale of Culhwch and Olwen, the stag is one of the oldest animals in the world, along with the blackbird, the owl, the eagle and the salmon.
The antlers of the stag are compared to tree-branches and thus may represent fertility. Since they are shed and re-grown every year, they may also symbolise rejuvenation and rebirth. Cernunnos, the Celtic Horned God, was depicted with the antlers of a stag; he is said to be a god of fertility and plenty, and to be the Lord of the Beasts. According to some, his antlers symbolise a radiation of heavenly light. Images of stags were supposedly used to symbolise Cernunnos in non-human form.