The Leanan Sídhe is a beautiful spirit, often female, who seduces a mortal lover. She (or he) is a dangerous muse, whose lovers devote themselves to the spirit in exchange for a short-lived, but remarkable artistic life. The Leanan Sídhe are considered vampiric, feeding on their lover’s life, so they can live in their stead. Many artists have wasted away, often dying young, unless they can convince another mortal to take their place. However, if the artist refuses the Leanan Sídhe, the spirit becomes their slave.
In Irish folklore, the Leannán Sí is one of the Aos Sí (people of the mounds). The name is Gaelic and means sweetheart, lover, or concubine.