Aesop was a slave who lived in ancient Greece around 620-564 BC. He is most famous for his fables, which use animals to teach moral lessons. Though the origins of some fables predate Aesop, hundreds are traditionally attributed to him. Aesop's fables have been translated into many languages and are still used today to teach children life lessons. Some of his most well-known fables include The Boy Who Cried Wolf, The Fox and the Grapes, and The Wolf in Sheep's Clothing.