Hecate was one of the original Titans, and who survived the war of the gods against them. She was beloved of Zeus and he took nothing from her and instead showered her with gifts. She remained in her power and worship. She is the goddess of the crossroads, entrance-ways, fire, light, Moon magic, witchcraft, herb-craft (including poisons), and death. She is heralded by hounds, and here she is with her boon companions.
She is Goddess of the WItches, and witchcraft, and so she is also seen as a goddess to call upon when the veil between the worlds are thinnest on Halloween.