A Harpy is the singular form for the mythical creatures called Harpies in Greek mythology, winged-beasts that were sent down by Zeus to punish, most famously the prophet Phineus. They were sometimes referred to as "the hounds of Zeus" for such actions.
Harpies were often described as bird-like creatures, no smaller than an eagle but usually not much larger. They had the hooked claws and beaks of a bird, but also left an over-powering stench where ever they went. Later, the Harpies were depicted as having the head of a human being, similar to gorgons and sirens as composite creatures; they were usually described as female. They are often associated with the wind and air, and thus are sometimes seen as representing the duality of the air: calm and graceful at times, but also capable of great destruction and chaos.
As the gods, Harpies were considered immortal. With their immortality, however they were often depicted as being insatiable, with emaciated bodies to the point of being corpse-like.
Originally the Harpies were conceived as spirits of the wind, the personification of a nature occurrence that is frequent in ancient cultures. The sky was a significant place for the ancient Greeks, and much like the deeper parts of the ocean, it was revered because it was inaccessible. Mount Olympus, the realm of the gods, was located high in the sky and so the atmosphere and weather became associated as the whims of the gods. Therefore, it is conceivable that the idea of the Harpies could have come from the consistently shifting winds. It was not until later that the Harpies were given a physical form, for the sake of story telling.
In their winged human form, the Harpies are no different from a large number of Greek divinities and as such would not need a special explanation for how they came to be. The later bird composite form is considered by most authors to have been confusion with an early depiction of the Sirens as bird women.
In Greek Mythology, Harpies were known to torment Phineus, a blind seer cursed by the gods, by stealing or defiling whatever food he would have. Here, the harpies symbolise a form of divine punishment, most notably the plague of famine.
Harpies were commonly associated with the Erinyes, more commonly known as the Furies, in likeness, leading some to believe that the Furies were harpies themselves. The Furies were divine beings known to torment oath-breakers, usually those who have betrayed blood-relations, tying back to associations with oaths and vengeance.
- Divine Punishment