The Goddess Epona helps to manifest dreams, and she is the goddess of horses and horsemen. She is most known for being the protector of travel (horses, mules and donkeys).
She was the only Celtic Goddess honored by the Romans by having a temple in their capital city. She was worshipped in Rome where her festival was held on December 18th.
She has a key which gives her access to the underworld & she's sometimes depicted half-naked, riding a horse.