In Asturian mythology, the xana is a fairy nymph of extraordinary beauty believed to live in fountains, rivers, waterfalls or forested regions with pure water.
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.
Always female, 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.
A xana is 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 have children, which are called xaninos, but because they cannot take care of them, 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. One must do this ritual in order to unmask the xanín: some pots and egg shells are to be put 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!".
The tales about xanas can be divided into four broad categories. First, stories in which the xana has a child. In these stories, the xana, for some reason, switches her baby for that of another woman. Second, stories of xanas who suffer spells. In these stories, an act performed according to a secret norm can disenchant them. Third, xanas who possess treasures and riches. The xana may have acquired the riches accidentally, or through donation or theft; sometimes the human character of the tale obtains the treasure, but most of the times he does not. Finally, stories about xanas who are malicious. The most important tales of this category are those in which the xana enters a home through a keyhole; those in which the xana takes and enchants someone; those in which the xana transforms into animals; and those in which the xana provides a magic belt. - El gran libro de la mitología asturiana, Xuan Xosé Sánchez Vicente and Xesús Cañedo Valle, Ediciones Trabe, 2003, p. 37-45.