South Italian winged sphinx. Sitting in a cabinet behind Freud’s desk, this 7-inch-high, terracotta sphinx dates to the late fifth century B.C. Unlike Egyptian and Assyrian sphinxes, which were usually depicted as males, Greek sphinxes often took female form, probably because the sphinx in the Greek myth of Oedipus is female. In that story, the sphinx kills (by eating) anyone who cannot solve a riddle she poses. When Oedipus answers the riddle, the sphinx flies into a rage and kills herself.