The Psychophage is a specialised predator grown in answer to the galaxy's witches and wielders of the warp. Where other organisms hunger for flesh, this loping, furnace-bellied beast hungers for psychic energy itself, drawn unerringly toward psykers and the ambient power they radiate. It closes with terrible speed and gouts searing bio-thermal flame, consuming both the body and the crackling soul-stuff of its prey.
Each mind it devours seems only to stoke the fires within, leaving the creature more vigorous and harder to put down. For the Hive Mind, the Psychophage is a scalpel aimed at the enemy's most dangerous assets, deployed to silence psykers, sorcerers, and battle-casters before their powers can turn the tide. It also serves the swarm defensively, dampening hostile witchfire in the region around it. To the Tyranids, even the power of the immaterium is simply another form of biomass to be hunted, harvested, and consumed.