Lady of the void.

A Lady of the Voids is a Daemon of the Chaos God Slaanesh, Prince of Pleasure, encountered within the Calixis Sector that lurks between the stars, seeking a way aboard an unwary vessel traversing the Immaterium by preying upon a Navigator or astropath. In a moment of weakness they can use an unfortunate victim to pass directly through a Gellar Field and into a vessel. When the Daemon manifests, its true form is horrific and is often enough to break a mortal's mind. With many voices the creature screams and moans in a dreadful Warp-song which enraptures all who hear it -- compelling these unfortunate souls to mutilate themselves, destroy equipment, open airlocks into the void and murder one another. A Lady of the Voids is a Daemon of the Chaos God Slaanesh, Prince of Pleasure, encountered within the Calixis Sector that lurks between the stars, seeking a way aboard an unwary vessel traversing the Immaterium by preying upon a Navigator or astropath. In a moment of weakness they can use an unfortunate victim to pass directly through a Gellar Field and into a vessel. When the Daemon manifests, its true form is horrific and is often enough to break a mortal's mind. With many voices the creature screams and moans in a dreadful Warp-song which enraptures all who hear it -- compelling these unfortunate souls to mutilate themselves, destroy equipment, open airlocks into the void and murder one another. In spacefarers' tales, the Lady of the Voids is the safe, oblique name given to a type of foul thing that lurks between the stars. They are the voices in the void, the witch–queens of Daemons who desire only to sunder vessels and tear the living breath from crewmen's bodies with a kiss. Their call is a siren's song that can send men mad, struggling to open their compartments to space or killing one another with nails and teeth. The Daemons that give rise to these fearsome tales are a nameless Slaaneshi breed that is often part of the vile host that trails any voidships.