Chrysaor enters Greek literature in Hesiod's Theogony within the genealogy of the Gorgons. Medusa is the mortal sister of the immortal Stheno and Euryale, and Hesiod says that the dark-haired god Poseidon lay with her in a soft meadow among spring flowers. When Perseus later cuts off Medusa's head, two beings spring from her: the horse Pegasus and great Chrysaor. The poem immediately explains both names. Pegasus is linked with the springs of Ocean, while Chrysaor is named because he holds a golden aor, a sword or blade, in his hands.

That ancient wording supports the golden sword as Chrysaor's clearest identifying symbol. It does not, however, say that he is born fully grown, wearing armour or already engaged in battle. Hesiod calls him great and gives him the weapon, but provides no description of his age, body or clothing. Pseudo-Apollodorus later confirms that Chrysaor and Pegasus are the children of Medusa and Poseidon. The safest reconstruction therefore stops short of the common modern image of a fully armed adult warrior leaping from Medusa's neck.

Chrysaor's next secure appearance is his union with Callirhoe, one of the Oceanids, daughters of Oceanus and Tethys. Hesiod says that Chrysaor and Callirhoe become the parents of Geryon, whom he describes as three-headed. Stesichorus' lost Geryoneis, surviving only in fragments, also remembers Geryon as the son of Chrysaor and Callirhoe. Through Geryon, Chrysaor becomes part of the western mythology of Erytheia and the cattle later taken by Heracles.

The surviving sources do not place Chrysaor in the battle between Heracles and Geryon. Hesiod tells how Heracles kills Geryon, Orthrus and the herdsman Eurytion and drives away the cattle, but Chrysaor does not appear to defend his son or fight the hero. This is an important distinction because later retellings sometimes turn the golden-sworded father into an active combatant. In the early evidence, Chrysaor functions mainly as a link in the genealogy rather than as the hero of an independent combat myth.

Echidna should also be handled cautiously. Immediately after the Chrysaor and Geryon passage, Hesiod says that 'she' bore the monster Echidna, but the feminine pronoun is ambiguous. Ancient and modern scholars have debated whether it refers back to Callirhoe or, more probably in many modern editions, to Ceto from the earlier Gorgon genealogy. Because of that ambiguity, it is too strong to present Echidna as a securely established daughter of Chrysaor and Callirhoe. Hyginus, for example, clearly gives Chrysaor and Callirhoe only the three-formed Geryon.

Chrysaor's birth should likewise be separated from the later Roman story of Medusa's transformation. Hesiod already knows Medusa as one of the Gorgons and does not tell a story in which Athena changes a beautiful maiden into a monster. Centuries later Ovid gives the famous version in which Neptune violates Medusa in Minerva's temple and Minerva transforms her beautiful hair into snakes. That Roman account became enormously influential, but it is a later layer and should not be treated as the background assumed by Hesiod's Chrysaor.

The name itself reinforces the sword image. The Greek adjective chrysaoros means golden-sworded or bearing a sword of gold and can also appear as an epithet of deities such as Apollo. Chrysaor the son of Medusa is a distinct mythological figure, but Hesiod's explicit explanation makes the weapon part of his identity from the moment of birth. Unlike Pegasus, Medusa or Geryon, he receives little independent ancient iconography or narrative development in the surviving corpus.

A much later use of the name appeared in modern cybersecurity. In 2017 Google and Lookout used Chrysaor for Android spyware related to the Pegasus surveillance system. The paired names deliberately recalled Medusa's two children, but this belongs to modern technical naming rather than to the ancient myth. It demonstrates how Chrysaor's brief ancient genealogy can still supply a recognisable name when placed beside his far more famous brother.