The ram-headed Criosphinx was a guardian of sacred Egyptian sites.  The Temple at Karnak was once connected to Luxor and the Nile by the Avenue of the Sphinx – a road flanked by dozens upon dozens of the implacable riddle keepers.

“And yet the riddle was not to be solved by guess-work but required the prophet's art; wherein thou wast found lacking; neither birds nor sign from heaven helped thee, but I came, the simple Oedipus; I stopped her mouth by mother wit, untaught of auguries.”

-- Oedipus, Oedipus Rex