Banshees are described in the Monster Manual as “the undead remnants of elves who, blessed with great beauty, failed to use their gift to bring joy to the world. Instead, they used their beauty to corrupt and control others. Elves afflicted by the banshee’s curse experience know no gladness, feeling only distress in the presence of the living. As the curse takes its toll, their minds and bodies decay until death completes their transformation into undead monsters.”