Nyx as known in Greek mythology is the Goddess and personification of the night. According to the writings of the ancient Greeks, she was one of the first goddesses. In Hesiod's Theogony she is the offspring of Chaos along with her siblings usually listed Erebus, Uranus, Gaia and Tartarus.

It is said even Zeus feared her as her powers outmatch the ones of the great God.

Throughout ancient Greek art Nyx often appears alongside other celestial deities such as Selene, Helios and Eos, as a winged figure driving a horse-pulled chariot.

More Info: en.m.wikipedia.org