Ekhion was born of the teeth of the Ismenian Dragon. Kadmos having killed the Drakon planted and sewed the teeth. Ekhion was among those born from the teeth. When Ekhion and the other Spartoi emerged, Kadmos panicked and threw a rock at them. Ekhion and all the others believed one of their own had thrown it. A fight ensued and in the end five survived. The survivors were Ekhion, Pelorus, Udaeus, Hyperenor and Khthonius.