Cernunnos, or as he is often called The Horned One. There is not much known about him today, so unfortunately there is little I can say of him, as he comes from the ancient Druadic tradition, which was an oral culture, and so there really are no written accounts of Cernunnos, the way he had aquired the name The Horned One, is becasue he is depicted as a man with a stags antlers.
The one thing that is known of him, is that he was the God of fertility, the beasts, life, and the underworld or as the Celtis frequently knew it, the Otherworld. It is also said that he was born in the winter solistice, and marries the Goddess during Beltane, then dies in the sumer solistice, and he is portrayed in connection with the sun, for it is said that he alternates with the Goddess of the Moon in rulting over life and death and contintue the cycle of death and rebrith.