The Wood Witches

Summary

A myth used to scare misbehaving children in many countries in the Old World. Different regions have different versions of this myth.
The common thread of the tale is that there is a magic user of some form that derives power from naughty children. Some it is their blood and they bleed them dry. Others it is their tears and they freighten them until they have no tears left. Others, it is a life force they need to feed off of.
The most famous of the myths is the Dreneth version of the myth.
The Wood Witches are gnarled old hags with pointed hats, greening skin, long noses, and are usually depicted with warts. It is said their warty, greening skin is rough like bark and that they live deep in the woods. To keep youthful and beautiful, they require the souls of naughty children.
They will come in the dead of night when everyone is sleeping and use their magics to make the child sleep walk with them into the deep of the woods. There, they would perform their terrible rituals. The child would remain asleep the whole time until their work was done. When their ritual was completed, the child would shrivel up like a dead leaf and the Wood Witches would gain all its naughty years.

Historical Basis

Though there has never been any evidence found of a cabal of 'Wood Witches', there have been rumours of dark magics powered by life for as long as there's been magic.
As magic is at its most powerful far from civilization, performing rituals in the woods would be the sensible place for them to be.
It is largely considered to be an exaggeration of people's worst fears of magic.
There have been claims over the years that they are the root of different missing children cases, but no concrete evidence has ever been found.

Cultural Reception

The Dreneth version is considered the most famous as it is the root of many common stereotypes found in television, film, and other novels. The visage of the crooked hag with green skin and warts is seared into the public conciousness and is a common character used to lampoon practitioners of magic.
It is also said to a tool used for prejudiced bigotry against active Magical groups in different countries.