According to the Byzantine author John the Lydian (c. AD 490 – 565), Hesiod, in his Catalogue of Women, states that Graecus is the son of Zeus and Pandora, daughter of Deucalion and Pyrrha, and says, in addition, that he has a brother, Latinus. The Byzantine author Stephanus of Byzantium (fl. 6th century AD) states that Graecus was a son of Thessalus.
Graecus was the eponym of the Graecians, a group of Hellenic people who lived westwards of the Hellenes mentioned by Homer. The Hellenic peoples collectively came to be known as Graeci in Latin, after the Graecians.
↑Although Zeus copulated with all of Pyrrha's daughters, he was presumably only the father of Hellen; cf. West (1985, p.56).
Footnotes
↑The name likely derives from graia (γραῖα), meaning "old woman" or "old," tied to graea, an ancient city in Boeotia, or early Greek peoples near Dodona.
Hard, Robin, The Routledge Handbook of Greek Mythology: Based on H.J. Rose's "Handbook of Greek Mythology", Psychology Press, 2004. ISBN978-0-415-18636-0. Google Books.