Lernaean Hydra
On hearing the commotion, Geryon sprang into action, carrying three shields, three spears, and wearing three helmets. He pursued Heracles at the River Anthemus but fell victim to an arrow that had been dipped in the venomous blood of the Lernaean Hydra, shot so forcefully by Heracles that it pierced Geryon's forehead, "and Geryon bent his neck over to one side, like a poppy that spoils its delicate shapes, shedding its petals all at once".