Banshees on Teen Wolf can hear voices in their heads. Often this leads them, subconsciously, to murder scenes. They sometimes write or draw messages from the voices subconsciously.
- EDITOR'S NOTE: While there is much written about this type of creature in the folklore of Ireland, Scotland, Wales and some other countries, it is unclear to what extent the legend may be altered within Teen Wolf.
While they get early indications that someone is going to die, their ability lacks precision and the banshees seen on show to date don't seem to be in complete control of their abilities. The only one to come close to full control is Lydia Martin.
Banshees are not supernatural. Chris Argent explains in Maid of Gevaudan that banshees have a connection to the supernatural but are not controlled by it. For example, Lydia can cross Mountain Ash barriers which no supernatural creature on the show can cross. She was unaffected by kanima venom and the effects of an Alpha werewolf's bite.
Similarities to Real World Legend
From what we know so far, Lydia has a few traits common to the Banshee of legend.
- Piercing Scream
We first saw just how far Lydia's scream carries in the Season 2 opener Omega. When she screamed after her hallucination at the hospital, Scott heard the sound at Allison's house and it seemed to reach far into the Beacon Hills Preserve as well.
- Harbinger of Death
Also in Omega, Lydia's wanderings in the woods ended up at a scene of death.
This connection was made clear in Season 3. As the rate of killings increased, Lydia increasingly found herself subconsciously drawn to the scenes.
Peter says Lydia's scream is a means to an end, drowning out all other sounds so that she can focus on the voices only she can hear. It appears that she is connected to some supernatural network that broadcasts messages about death and dying. According to Teen Wolf Creator Jeff Davis it is "the whispers of other banshees."
This was seen in Motel California when she heard the voices of the people killed at the motel, in Riddled as she heard Stiles' voice coming from a speaker and other whispers when she plucked the strings in his bedroom.
Peter uses Lydia to listen to the whispers from his sister's claws in Letharia Vulpina and learns he has a child.
The Nogitsune kidnaps Lydia to use her power so that he will know when the Oni are close enough to kill him. Lydia is also able to communicate with a fellow Banshee, Meredith Walker, to tell Stiles that she doesn't want to be found (see Insatiable).
In Season 5, Meredith says they can use their scream as a offensive weapon as well. The scream is seen as a strong sound wave capable of throwing people and objects short distances. According to Dr. Valack, in The Last Chimera, she could shatter a human skull with her voice as well. This is evidenced in Lie Ability as Valack, himself, meets this fate.