The banshee has its origins in the legends of Ireland. She is said to be a spirit that screams out. If one hears it, they know it is a harbinger of a death of a loved one that is imminent.
LINK: powers to become the harbinger of coming doom to her mortal kindred. Or she may be seen at night as a shrouded woman, crouched beneath the trees, lamenting with veiled face, or flying past in the moonlight, crying bitterly. And the cry of this spirit is mournful beyond all other sounds on earth, and betokens certain death to some member of the family whenever it is heard in the silence of the night.