Oncus
Ὄγκος
(Ὄγκος), a son of Apollo, and founder of Onceium in Arcadia. Demeter, after being me tamorphosed ilto a horse, mixed among his herds, and gave him the horse Arion, of which she was the mother by Poseidon. (Paus. 8.25.4, &c.; comp. Step. Byz. s. v.)
From William Smith (ed.), Dictionary of Greek and Roman Biography and Mythology. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.