Xana

The xana is a character found in Asturian mythology. Always female, she is a creature of extraordinary beauty believed to live in fountains, rivers, waterfalls or forested regions with pure water. She is usually described as small or slender with long blonde or light brown hair (most often curly), which she tends to with gold or silver combs woven from sun or moonbeams. The origin of the Asturian word xana is unclear, though some scholars see it as a derivation from the Latin name for the goddess Diana. References to where the mythological xanas lived are still common in Asturian toponyms. They also appear in Eastern Galician and Cantabrian mythology (Anjanas).

The xanas promise treasures and can be disenchanted. Some xanas also attack people and steal their food. They live in fountains and caves.

A xana can be a beneficial spirit, offering love water to travelers and rewards of gold or silver to those found worthy through some undefined judgment. Their hypnotic voices can be heard during spring and summer nights. Those who have a pure soul and hear the song will be filled with a sense of peace and love. Those whose souls are not pure will feel they are being suffocated and may be driven insane.

Xanas are usually depicted in one of two ways. In one, they appear as young Nordic girls, very beautiful, with long blonde hair. This image is usually associated with xanas who possess a treasure or those under a spell. In contrast, in tales in which the xanas steal children and enter homes to bite or steal, the xanas are small, thin and dark-colored.

Xanas have children, which are called xaninos, but because they cannot take care of them—xanas cannot produce milk to feed their babies—they usually take a human baby from his cradle and put their own fairy child in instead (see changelings). The human mother realizes this change when the baby grows up in just a few months. In order to unmask the xanín, one must put some pots and egg shells near the fire, and, if the baby is a changeling, he will exclaim, "I was born one hundred years ago, and since then I have not seen so many egg shells near the fire!"

...
Wikipedia