|Parents||Pontus and Gaia|
|Siblings||Nereus, Thaumas, Phorcys and Eurybia|
|Children||The Hesperides, The Gorgons, The Graeae, Thoosa, Scylla, Echidna, Ladon and all sea Monsters|
Ceto or Keto (Ancient Greek: Κητώ, Kētō, "sea monster"), is a primordial sea goddess in Greek mythology, the daughter of Gaia and Pontus. Ceto was also variously called Crataeis (Κράταιις, Krataiis, from κραταιίς "mighty") and Trienus (Τρίενος, Trienos, from τρίενος "within three years"), and was occasionally conflated by scholars with the goddess Hecate (for whom Trienus and Crataeis are also epithets). As a mythological figure, she is most notable for bearing by Phorcys a host of monstrous children, collectively known as the Phorcydes. The small solar system body 65489 Ceto was named after her, and its satellite after Phorcys.
This goddess should not be confused with the minor Oceanid also named Ceto — who appears in Hesiod's Theogony as a separate character from Ceto the daughter of Pontus and Gaia — or with various mythological beings referred to as ketos (plural ketea); this is a general term for "sea monster" in Ancient Greek.
Ceto in ancient texts
Hesiod's Theogony lists the children of Phorcys and Ceto as Echidna, The Gorgons (Euryale, Stheno, and the infamous Medusa), The Graeae (Deino, Enyo, Pemphredo, and sometimes Perso), and Ladon, also called the Drakon Hesperios ("Hesperian Dragon", or dragon of the Hesperides). These children tend to be consistent across sources, though Ladon is sometimes cited as a child of Echidna by Typhon and therefore Phorcys and Ceto's grandson.
The Bibliotheca and Homer refer to Scylla as the daughter of Crataeis, with the Bibliotheca specifying that she is also Phorcys's daughter. The Bibliotheca also refers to Scylla as the daughter of Trienus, implying that Crataeis and Trienus are the same entity. Apollonius cites Scylla as the daughter of Phorcys and a conflated Crataeis-Hecate. Stesichorus refers to Scylla as a daughter of Phorcys and Lamia (potentially translated as "the shark" and referring to Ceto rather than to the mythological Libyan Queen).
Pliny the Elder mentions worship of "storied Ceto" at Joppa (now Jaffa), in a single reference, immediately after his mention of Andromeda, whom Perseus rescued from a sea-monster. S. Safrai and M. Stern suggest the possibility that someone at Joppa established a cult of the monster under the name Ceto. As an alternative explanation, they posit that Pliny or his source misread the name cetus — or that of the Syrian goddess Derceto.
Ceto in popular culture
Ceto appears in Rick Riordan's Mark of Athena, where she and her brother-husband Phorcys run an aquarium featuring shows by sea monsters and other underwater mythological creatures called "Death in the Deep Seas" (Sponsored by Monster Donut) out of the Georgia Aquarium. Percy Jackson and Frank Zhang, both descended from Poseidon, are imprisoned by Phorcys. They are rescued by the satyr Gleeson Hedge, who kicks Ceto in the head and rescues Percy and Frank. This angers Ceto, so she sends a giant scolopendra to attack their ship, the Argo II, but it is defeated by the ichthyocentaurs, who promise to defeat Ceto and Phorcys.
- "κῆτος" in Liddell, Henry and Robert Scott. 1996. A Greek-English Lexicon. Revised by H.S. Jones and R. McKenzie. Ninth edition, with revised supplement. Oxford: Clarendon Press.
- Colitur illic fabulosa Ceto. Pliny, Book 5, chapter 14, §69; this same paragraph will be referred to as v.14, v.69, V.xiv.69; and v.13 (one of the chapter divisions is missing in some MSS). For Ceto as a transferred name, see Rackham's Loeb translation; for emendations, see The Jewish people in the first century. Historical geography, political history, social, cultural and religious life and institutions. Ed. by S. Safrai and M. Stern in co-operation with D. Flusser and W. C. van Unnik, Vol II, p. 1081, and Oldfather's translation of Pliny (Derceto).