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Banes are folkloric creatures; pale young virgins who are said to inflict death and disease on children as they walk the villages at daybreak. They are mentioned by the alderman in Upper Posada in the short story "The Edge of the World".
|“||Bane! said one. Aye, aye, 'tis true what the alderman says. A pale virgin, she walks the cottages at daybreak, and the children, they die!||”|
— pg(s). 165, The Last Wish (UK edition)
It's uncertain whether these are the same creatures as virgin banes which are said to affect cattle and milk production. Virginity does seem to be a common characteristic.