A hag (or crone) is a wizened old woman, or a kind of fairy or goddess having the appearance of such a woman, often found in folklore and children's tales such as Hansel and Gretel. Hags are often seen as malevolent, but may also be one of the chosen forms of shapeshifting deities, such as the Morrígan or Badb, who are seen as neither wholly beneficent nor malevolent. The term appears in Middle English, and might be short for hægtesse, an Old English term for witch.
In Irish and Scottish mythology, the Cailleach is a hag goddess concerned with creation, harvest, the weather and sovereignty. In partnership with the goddess Brìde, she is a seasonal goddess, seen as ruling the winter months while Brìde rules the summer. In Scotland, a group of hags, known as The Cailleachan (The Storm Hags) are seen as personifications of the elemental powers of nature, especially in a destructive aspect. They are said to be particularly active in raising the windstorms of spring, during the period known as A Chailleach.
Hags as sovereignty figures abound in Irish mythology. The most common pattern is that the hag represents the barren land, who the hero of the tale must approach without fear, and come to love on her own terms. When the hero displays this courage, love, and acceptance of her hideous side, the sovereignty hag then reveals that she is also a young and beautiful goddess.
The Three Fates (particularly Atropos) are often depicted as hags.
In Persian folklore, the Bakhtak has the same role as that of "the Old Hag" in British folklore. The Bakhtak sits on a sleeper's chest, awakening them and causing them to feel they are unable to breathe or even to move. Bakhtak also is used metaphorically to refer to "nightmare" in the modern Persian language.
Many stories about hags seem to have been used to frighten children into being good. Peg Powler, for example, was a river hag who lived in river trees and had skin the color of green pond scum. Parents who wanted to keep their children away from the river's edge told them that if they got too close to the water she would pull them in with her long arms, drown them, and sometimes eat them. Peg Powler has other regional names, such as Jenny Greenteeth from Yorkshire and Nellie Longarms from several English counties.
Many tales about hags do not describe them well enough to distinguish between an old woman who knows magic or a supernatural being.
Hags are occasionally mentioned in the Harry Potter series, but never in any great detail (the prologue of "Fantastic Beasts and Where to Find Them" mentions that they are classed as beings (as opposed to beasts) that children are part of their diet and that they can glide). Hags are occasionally encountered in the wizarding village Hogsmeade, where they are distinguished from "conventional" wizards and witches. It is unclear if such Hags live in Hogsmeade or simply visit the village for business and/or social reasons.
Hags are also mentioned in the Chronicles of Narnia book series. In The Lion, the Witch and the Wardrobe, Hags are one of the various kinds of evil creatures whom the White Witch has present at the killing of Aslan. Later, in Prince Caspian, a Hag, along with a Werewolf and the dwarf Nikabrik, tries to persuade Caspian to summon the Witch back to life. They attack after being refused, and are killed.
In the Popeye comics and cartoons, Popeye is sometimes pursued by a villainous witch called Sea Hag, who has an unrequited love for the sailor.