I am Sphinx!

Continuing his journey to Thebes, Oedipus encounters the Sphinx who would stop all those who traveled to Thebes and ask them a riddle. If the travelers were unable to answer correctly, they were eaten by the Sphinx; if they were successful, they would be able to continue their journey. The riddle was: "What walks on four feet in the morning, two in the afternoon and three at night?". Oedipus answers: "Man; as an infant, he crawls on all fours, as an adult, he walks on two legs and, in old age, he relies on a walking stick". Oedipus was the first to answer the riddle correctly. Having heard Oedipus' answer, the Sphinx is astounded and throws herself to her death from a clifftop. Grateful, the people of Thebes appoint Oedipus as their king and give him the recently widowed Queen Jocasta's hand in marriage. (The people of Thebes believed her husband had been killed while on a search for the answer to the Sphinx's riddle. They had no idea who the killer was.) The marriage of Oedipus and Jocasta fulfilled the rest of the prophecy. Oedipus and Jocasta have four children: two sons, Polynices and Eteocles (see Seven Against Thebes), and two daughters, Antigone and Ismene.