Greek Mythology/Stories/The Sphinx
The Sphinx was an ancient Egyptian creature that had the body of a winged lion, and the face of a woman. She terrorized the city of Thebes like this: she would ask anybody traveling on the road to Thebes a riddle. If they answered it, she would let them go. However, if they didn't say the right answer, she would kill them. This continued for a long time, until one day, a stranger by the name of Oedipus encountered the Sphinx on the way to Thebes. The sphinx asked him this riddle: What creature goes on four feet in the morning, two at noonday, and three in the evening?
Oedipus correctly answered man, and the sphinx gruesomely killed herself by jumping from a high rock. An alternative version tells that she devoured herself. (The answer to the riddle is man, since a man crawls on four feet when he is very young [morning], walks on two feet in the middle of his life [noonday], and walks with the help of a cane [the 'third leg'] near the end of his life [evening])