
The image of a sphinx is one of a lion in a recumberant position with the head of either a falcon, ram or of a person. It was invented by the Egyptians and as such is seen in their famous 'valleys of the kings. It is a mythical creature and is a guardian in the statuary of Egyptians.
The most famous sphinx (and the largest) is the Great Sphinx of Giza which is situated on west bank of the Nile, facing due east, on the Giza plateau. It is thought to be the head of the great pharaoh Khafra or possible of his son Djedefra. This would put the date of its construction at sometime in the fourth dynasty. Unlike Greek sphinxes the Egyptian version will always have the head of a man rather than woman.
In Greek mythology there was a single sphinx and she was the bearer of bad luck and destruction. She was shown in a lot of vase painting and was always pictured upright rather than recumberant. She had a womans head and wings on the body of a lion, or else was in a female form with the head, paws and chest of a lion with an eagles wings and a serpent's tale. Legend has it that she was sent from her Ethiopian homeland by Hera or Ares to Thebes and would ask all passersby the question "what goes on four feet in the morning, two by noon and three in the evening?" it is said that she strangled anyone unable to answer. Oedipus was the only one that was able to answer the question 'man' and at this point she reportedly threw herself down from her seating point and died. In some versions of the tale she actually devoured herself.
The word comes from a Greek verb meaning 'to strangle'.