Ceto (Ancient Greek Kētṓ, literally "sea monster") is a primordial sea goddess in Greek mythology, the daughter of Pontus (Sea) and his mother Gaia (Earth). One of the most ancient deities, she became the sister-wife of Phorcys, by whom she bore a brood of monstrous offspring — chiefly the Gorgons and the Graeae. She should not be confused with a minor Oceanid of the same name, nor with the common noun ketos, the general Greek term for a sea monster.
Adapted from Wikipedia, "Ceto" · CC BY-SA 4.0
I.Name and identity
Ceto (Ancient Greek: Κητώ, romanized Kētṓ) takes her name from the word meaning "sea monster." She was also variously called Crataeis (Κράταιις, from κραταιίς, "mighty") and Trienus (Τρίενος, from τρίενος, "within three years"). Because Crataeis and Trienus are likewise epithets of Hecate, scholars occasionally conflated the two goddesses.
This primordial sea goddess should not be confused with the minor Oceanid also named Ceto, nor with the various mythological beings referred to as ketos (plural kētē or ketea), this being a general term for "sea monster" in Ancient Greek.
Ceto ranks among the most ancient deities of Greek myth. The small Solar System body 65489 Ceto was named after her, and its satellite after Phorcys.
II.Family
Ceto is the daughter of Pontus (Sea) and Gaia (Earth). Besides Ceto, Gaia and Pontus had four other offspring: Nereus, Thaumas, Phorcys, and Eurybia. Ceto became the consort of her brother Phorcys, and together the two produced a line of monstrous children.
Hesiod's Theogony lists the children of Ceto and Phorcys as the two Graiae (Pemphredo and Enyo) and the three Gorgons (Sthenno, Euryale, and Medusa), with their final offspring being an unnamed serpent — later called Ladon — that guards the golden apples. Hesiod also says that a "she" bore Echidna, half-woman and half-snake; this mother is probably Ceto, though possibly the Oceanid Callirhoe. Pherecydes makes Echidna a daughter of Phorcys without naming the mother.
Apollodorus and Hyginus name three daughters of Ceto and Phorcys — Pemphredo, Dino, and Persis — collectively the Graeae. These mythographers, however, make Ladon the offspring of Echidna and Typhon rather than of Ceto and Phorcys. A scholiast names Phorcys and Ceto as parents of the Hesperides, though this is unsupported elsewhere.
Ceto is possibly also reckoned the mother of the Nemean lion and the Sphinx by her grandson Orthrus. Homer refers to Thoosa, the mother of Polyphemus in the Odyssey, as a daughter of Phorcys, without indicating whether Ceto was her mother.
III.Cult
Pliny the Elder mentions the worship of "storied Ceto" at Joppa (modern Jaffa), recording it immediately after his notice of Andromeda, whom Perseus rescued from a sea monster.
The scholars Safrai and Stern suggest that someone at Joppa may have established a cult under this name. Alternatively, they propose that Pliny misread "cetus," or that he confused Ceto with the Syrian goddess Derceto.