In Greek mythology the Sphinx is a unique demon of destruction — a winged lioness with a woman's face — who sat before Thebes and killed travellers who failed her riddle until Oedipus answered correctly and she destroyed herself. Greek tradition thus differs sharply from the Egyptian androsphinx, typically a benevolent, wingless royal guardian. Hesiod and Apollodorus place her among the brood of Typhon and Echidna (or of Orthrus), and her emblem later marked the coinage of Chios.
Adapted from Wikipedia, "Sphinx" · CC BY-SA 4.0
I.Greek form and family
Unlike the Egyptian sphinx, usually male, wingless, and protective, the Greek Sphinx is treacherous and merciless: a woman's head, a lion's haunches, and a bird's wings. Apollodorus gives her a woman's face, a lion's body and tail, and bird wings; Statius and Tzetzes add gore-clotted plumes, griffin wings, or eagle claws. Sometimes the wings are an eagle's and the tail serpent-headed.
Hesiod makes her a daughter of Orthrus by an uncertain mother (Chimera, Echidna, or Ceto). Apollodorus and Lasus instead name Echidna and Typhon as her parents. She was remembered as a foreign Aethiopian monster sent against Thebes — the Greeks never forgot that foreign origin.
II.The riddle of Thebes
Hera or Ares was said to have sent her from Aethiopia to Thebes, where she guarded the approach and propounded a riddle to every passer-by. Early tellers left the wording open; later lore fixed the famous question: which creature has one voice and yet becomes four-footed, two-footed, and three-footed? She strangled and ate those who failed.
Oedipus answered that the creature is man — crawling as an infant, walking upright in maturity, and leaning on a staff in old age. Bested, she threw herself from her high rock and died; some versions have Oedipus kill her, or have her devour herself. A rarer second riddle asked about two sisters who each give birth to the other — day and night (both feminine nouns in Greek).
III.Egypt and later reception
Egyptian sphinxes — above all the Great Sphinx of Giza — were guardian images of pharaonic power, often flanking temple approaches; Greek travellers such as Herodotus already applied the name sphinx to those statues before Alexander. Renaissance Europe revived a Mannerist "French sphinx" from Domus Aurea grotesques, while nineteenth-century Symbolists and Decadents returned to the Greek murderous femme fatale of the Oedipus myth.
The Sphinx of Chios appeared on seals and coins from the sixth century BC into the Roman period, fixing the Greek hybrid as a civic emblem distinct from the Egyptian type.