Erebus

Erebus (or Erebos) was the Protogenos of darkness and the brother and consort of Nyx. He was the son of Khaos and his name became associated with a region in the Underworld, Erebos.

Etymology
In Ancient Greek, Ἔρεβος (Érebos) means "deep darkness, shadow" or "covered". It also is cognate with Sanskrit rájas, Gothic riqis , and Old Norse røkkr. . All these words are originated from Proto-Indo-European *h₁régʷos.

Myths
Aside from the greek creation myth, the Theogeny, there isn't much, if at all, in terms of mentions of Erebus; the exception being mentions of a region in the underworld as previously mentioned, Erebos.