For 10 points, name this founder of Thebes.
According to legend, this man brought Greece the alphabet. When Illyria was destroyed, Zeus turned this figure and Harmonia into black serpents and sent them to the Elysian Fields. This man was ordered by the oracle at Delphi to cease his quest to find his sister (*) Europa and to settle at the spot where a cow lay down. This man created a race of armed men known as Spartoi after planting dragon's teeth. For 10 points, name this founder of Thebes.
According to legend, this man brought Greece the alphabet. When Illyria was destroyed, Zeus turned this figure and Harmonia into black serpents and sent them to the Elysian Fields.
{Cadmus}