Banshee


 * 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.

Lydia Martin is a Banshee, a harbinger of death within the Teen Wolf Universe.

Similarities to Real World Legend
From what we know so far, Lydia has a few traits common to the Banshee of legend.

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.
 * Piercing Scream

Also in Omega, Lydia's wanderings in the woods ended up at a scene of death.
 * Harbinger of Death

This connection was made clear in Season 3 as the rate of killings increased and Lydia increasingly found herself subconsciously drawn to the scenes.

Banshee Abilities
Peter says her scream is simply 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).