What is "whiro"

In Māori mythology, Whiro (or Hiro in the Tuamotus) is the lord of darkness, or the embodiment of all evil. He is the brother and enemy of Tāne. He inhabits the underworld and is responsible for the ills of all persons. In some versions of this story, when people die, their bodies descend into the underworld, where they are eaten by Whiro. Each time Whiro eats a body, he becomes stronger. This process will eventually make him sufficiently powerful to break free of the underworld, at which point he will come to the surface and devour everything and everyone on it. Cremation is therefore recommended to prevent this, because Whiro cannot gain strength from ashes.