Udaeus was born of the teeth of the Ismenian Dragon. Udaeus having killed the Drakon planted and sewed the teeth. Udaeus was among those born from the teeth. When Udaeus and the other Spartoi emerged, Kadmos panicked and threw a rock at them. Udaeus 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.