Ophion

In some versions of Greek mythology, Ophion (; "serpent"; "gen".: Ὀφίωνος), also called Ophioneus () ruled the world with Eurynome before the two of them were cast down by Cronus and Rhea. 
Mythology.
Pherecydes of Syros's "Heptamychia" is the first attested mention of Ophion.
The story was apparently popular in Orphic poetry, of which only fragments survive.
Apollonius of Rhodes in his "Argonautica" (1.495f) summarizes a song of Orpheus:
Lycophron (1191) relates that Zeus' mother, Rhea, is skilled in wrestling, having cast the former queen Eurynome into Tartarus.
Nonnus in his "Dionysiaca" has Hera say (8.158f):
"Harmonia" here is probably an error in the text for "Eurynome". Ophion is mentioned again by Nonnus (12.43):
We also have fragments of the writings of the early philosopher Pherecydes of Syros (6th century ), who devised a myth or legend in which powers known as Zas and Chronos ("Time") and Chthonie ("Of the Earth") existed from the beginning and in which Chronos creates the universe. Some fragments of this work mention a birth of Ophioneus and a battle of the gods between Cronus (not Chronos) on one side and Ophioneus and his children on the other in which an agreement is made that whoever pushes the other side into "Ogenos" will lose and the winner will hold heaven.
Eusebius of Caesarea in his "Praeparatio Evangelica" (1.10) cites Philo of Byblos as declaring that Pherecydes took Ophion and the Ophionidae from the Phoenicians.
Interpretations.
Robert Graves (1955) imaginatively reconstructs a Pelasgian creation myth in his book "The Greek Myths", involving a serpent “Ophion”:
Graves’ re-interpretation is very similar to some Gnostic traditions, with the demiurge (often represented as a serpentine “Yaldabaoth”) claiming to have created the world alone, despite the assistance of others. That assistance often is from “Sophia”, who is represented as (or allied with) the Holy Spirit, hence her symbolism includes doves.