Black Breath
From Tolkien Gateway
The Black Breath was a weapon used by the Nazgûl.
History
The Ringwraiths were surrounded by an aura of terror, which affected all living creatures; their breath was poisonous, and their cries caused terror and despair in all who heard them. The most notorious victims of the Black Breath were Meriadoc Brandybuck and Éowyn. It was dispelled from them by Aragorn at his return with athelas.