Banshees

A banshee is a female spirit in Irish mythology who heralds the death of a family member, usually by shrieking or keening. Her name is connected to the mythologically-important tumuli or "mounds" that dot the Irish countryside, which are known as síde (singular síd) in Old Irish.

The banshee is often described in Gaelic lore as wearing red or green, usually with long, disheveled hair (usually described as red or orange, and yellow in medieval times described to shimmer like wild fire). She can appear in a variety of forms. Perhaps most often she is seen as an ugly, frightful hag, but she can also appear young and beautiful if she chooses. In some tales, the figure who first appears to be a banshee or other cailleach (hag) is later revealed to be the Irish battle goddess, Morrígan.

DC Comics
The Silver Banshee, whose real name is Siobhan McDougal is a fictional comic book super-villain and a character featured in titles published by DC Comics. Traditionally presented as a foe of Superman, she first appeared in Action Comics 595 in December, 1987 in a story titled "The Ghost of Superman". The character was re-imagined for DC's "New 52" continuity, where she first appeared in Supergirl, Volume 6 #6 in April, 2012.

Siobhan came to New York City to escape her homeland of Ireland due to family issues. Her father died when she was young and her mother had only recently died which caused her to seek a new life in what she considered the "greatest city in the world". After arriving and settling down in Queens she inadvertently found herself face to face with the city's newest threat, Supergirl.

Instantly understanding her language, and after a short tussle with the authorities, she escaped with the help of Supergirl. Figuring that they needed each other and striking a fast friendship, the girls returned to Siobhan's home where they got to know each other properly. Siobhan decided to bring Kara to her latest band gig, and while playing music at the club, Siobhan's father, the Black Banshee. Siobhan revealed that she was, in fact, the Silver Banshee, and together they tackled her unrelenting father.

Teen Wolf
On the MTV television series Teen Wolf, high school student Lydia Martin comes into her own as a banshee after being reborn from a near fatal incident. Her primary abilities consisted of harrowing visions - many of which were not entirely clear, but they always signaled a pending death, or related to someone who was recently deceased. As part of Scott McCall's "pack", Lydia's visions became immensely important in terms of giving the group a direction by which to resolve a current crisis.

As time went on, Lydia also developed a sonic scream. Though mostly designed for offensive attack, Lydia's banshee cry had other effects as well, such as determining the course of an electric current that lead to a power sub station where a man named William Barrow had kidnapped Kira Yukimura.