Nothing is known about how the Physokerme came into being. Theories abound on whether or not it is some forgotten Tyranid lifeform or just an abomination.

The Physokerme hovers just above the ground, is protected by a psychic barrier of some sort, and it lashes out with blasts of pure warp energy. Its similarities to the Tyranid Zoanthrope are obvious, though the Physokerme creature is no where near as dangerous.

They often appear in large groups of five, randomly blasting anything that moves. It is believed that these creatures actually feed in this manner, somehow absorbing sustenance from their prey.