According to ancient lore, they are the souls of young maidens who were left guarding the treasures that the mouros encantados (enchanted mouros) hid before heading to the Mourama. The legends describe the mouras encantadas as young maidens of great beauty or as charming princesses who are "dangerously seductive". The mouras encantadas are shapeshifters and there are a number of legends, and versions of the same legend, as a result of centuries of oral tradition. They appear as guardians of the pathways into the earth and of the "limit" frontiers where it was believed that the supernatural could manifest itself.Mouras encantadas are magical maidens who guard castles, caves, bridges, wells, rivers, and treasures. There is a possibility that the mouras encantadas may have had assimilated the characteristics of local deities, such as nymphs and spirits of nature. They are also referred to as "feminine water genies". The tales of the mouras are part of a wider lore of the "mouros encantados", who some times appear as giants or warriors, which also include the mourinhos or maruxinhos, a very small elf like people who live under the ground.
These fairy tales featuring Mouras Encantadas are thought to be of pre-Roman, Indo-European Celtic origin. They are related to other Indo-European, and especially Celtic, female divinities of the water. Almost every Portuguese or Galician town has a tale of a Moura Encantada. The lore of the mouros encantados is used to find prehistoric monuments and was for some time used in the 19th century as the main method to locate lusitanian archaeological «monuments», a kind of folk memory that was erased with the Christianization. The mouras are also believed to be builders of ancient monuments.
Some variants of the generic "moura encantada" include:
- Princesa moura - She appears as a snake with long blond hair. In some fairy tales, the beings are beautiful muslim princesses (princesa moura) who live in castles at the time of the Reconquest, and fall in love with a Portuguese Christian knight. In other fairy tales, a moura encantada lives in a castle under the earth and falls in love with a Moor instead of the Christian knight. These two variations are found only in Portugal. Many of these legends try to explain the origins of a city or invoke historical characters, other legends present a religious context. In the historical context, these places, people and events are situated in the real world and in a specific time frame. It is believed that real historic facts have merged with old legend narrations.
- Moura-fiandeira - In other variants, the moura encantada is a Spinning maiden Moura (Moura-fiandeira), who carries stones on her head to build the hill forts while she spins the yarns with a Distaff that she carries at her waist. The mouras encantadas were believed to be the builders of the Paleolithic hill forts, the dolmens, and the megaliths. They are believed to still live there. The ancient coins found on the hill forts were called "medals of the mouros". The Pedra Formosa found on Citânia de Briteiros was, according to folklore, brought to this place by a moura who carried it on her head while she was spinning with a spindle. They are also night weavers, but only the sound of weaving can be heard in the night.
- Pedra-Moura - mouras encantadas who lived inside stones are named pedra-moura. It was believed that who ever sat on one of these stones would become enchanted, or, that if any enchanted stone was taken to a house, all the animals in the house could die. It was also believed that pedras mouras had enchanted treasures inside them. There are several legends where the moura instead of being a stone lives inside the stone. In Portuguese lore it is said that you can walk into or walk out of certain rocks, possibly related to the moura legends. The moura is, also, described as traveling to the “mourama” (an enchanted place) while sitting on a stone that can float in the air or water. Inside caves, under rocks and under the earth many legends say there exist palaces with treasures. According to Thurnwald (cited in McKenna, 1938), it was not uncommon among the people of pre-roman Iberian Peninsula to believe that the souls of the dead dwell in certain rocks. The "almas dos mouros" or "alminhas dos mouros" (souls or little souls of the mouros) was the name given to the votive aras, being "alminhas" the common name for the Wayside shrine.
- Moura-serpente - In some tales, the moura encantada is a shapeshifter who takes the form of a snake or cobra (Moura-cobra) (some times of a dog (cão), goat (cabra) or horse (cavalo)). These moura snake may have wings and can appear as half woman and half animal and like to be offered milk.
- Moura-Mãe - In some tales she is called mother-moura and takes the form of a charming young lady who is pregnant, and the narrative focuses on the search for a midwife to help at the birth and the reward that is given to the person who is willing to help.
- Moura-Velha- The moura-velha is an old woman; the legends where she appears with the shape of an old woman are no longer very frequent.
- Moura-lavadeira - she is a washerwoman but she is only seen putting white clothes out in the sun, contrary to the Lavandières who wash blooded stained clothes, the mouras are more like the lavadeiras.
- Frades (lit: friars) are mouras encantadas who appear like frades dressed in white. Frades are white stone pillars.