An contratained version of “the riddle of the sphinx”.

For those who want to know more on Greek mythology: the sphinx sat outside of Thebes and asked this riddle of all travelers who passed by. If the traveler failed to solve the riddle, then the Sphinx killed him/her. The riddle was ‘

What goes on four legs in the morning, on two legs at noon, and on three legs in the evening?’

Oedipus (yes the one from the complex) solved the riddle, and the Sphinx commited suicide.