The Spartoi were a mythical people in Greek mythology, who sprang out of the earth.
Their first appearance was in the founding myth of Thebes by Cadmus. He was instructed by the oracle of Delphi to follow a cow and found a city where the animal would stop. When the cow stopped, Cadmus decided to sacrifice it to the gods, so he asked his men to bring some water from a close-by spring. However, the spring was guarded by a dragon that was sacred to the god of war, Ares. Many of Cadmus' men died by the dragon, before Cadmus took his sword and killed it. Afterwards, the goddess Athena gave Cadmus half of the dragon's teeth and instructed him to sow them. As soon as he did that, armed soldiers sprang out of the earth; the Spartoi. Afraid, Cadmus threw a rock amidst them, who thought that one of them had thrown it; so, they started killing each other, and only five survived; Echion, Udaeus, Chthonius, Hyperenor, and Pelorus. The five Spartoi helped Cadmus found the city of Thebes. Cadmus was told to serve Ares for eight years as punishment for killing the sacred dragon.
The other appearance of the Spartoi is in the myth of Jason and the Argonauts. Athena had gifted the other half of the dragon's teeth to the king of Colchis, Aeetes. When Jason arrived there and asked to take to golden fleece, Aeetes told him to pass a series of tests. One of them was to sow the dragon's teeth, which Jason did. The Spartoi sprang up and Jason used the same trick as Cadmus, by throwing a rock amidst them. The Spartoi started fighting each other until no one remained.