Regrow Liver

And ready-witted Prometheus he bound with inextricable bonds, cruel chains, and drove a shaft through his middle, and set on him a long-winged eagle, which used to eat his immortal liver; but by night the liver grew as much again everyway as the long-winged bird devoured in the whole day. That bird Heracles, the valiant son of shapely-ankled Alcmene, slew; and delivered the son of Iapetus from the cruel plague, and released him from his affliction -- not without the will of Olympian Zeus who reigns on high, that the glory of Heracles the Theban-born might be yet greater than it was before over the plenteous earth.


- Hesiod, The Theogony, Prometheus