Hero Water is a special liquid available in the kingdom of Arabasta.
The Hero Water gives the drinker superhuman strength. However, the drinker will die within five minutes. Those who drink the Hero Water can easily be recognized by seeing strange markings on their arms (veils).
The Hero Water was used by the Tsumegeri Guards of Arabasta in an attempt to defeat Crocodile, knowing full well that their lives would be forfeit in five minutes. Crocodile easily evaded their enhanced powers with his intangible Suna Suna no Mi powers, and being cruel and ruthless, refused to even fight them to give them an honorable death, mocking them for their stupidity when they succumbed to the poison.