In Greek mythology, Lycus ( ; ), also called Lycaon,Scholia on Apollonius Rhodius, Argonautica 4.1561, referring to Philarchus for the alternate names was a son of Poseidon and Celaeno, one of the Pleiades.Hyginius Fabulae 157Apollodorus, 3.10.1 He was settled in the Fortunate Isles by his father.
References
Apollodorus, The Library with an English Translation by Sir James George Frazer, F.B.A., F.R.S. in 2 Volumes, Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1921. Online version at the Perseus Digital Library. Greek text available from the same website.