Stealth infantry unit.
The Lictor is a highly specialised development of the Tyranid Warrior bioform, specifically adapted to fill a scout role in the vanguard of the Tyranid advance. Lictors rove ahead of the main body of a swarm, seeking out pockets of resistance to be eradicated and native life forms to be absorbed. Able to move swiftly and without sound through even the densest terrain, and concealed by a chameleonic carapace that renders it all but invisible to the naked eye, a Lictor can remain hidden until it chooses to strike. It can wait motionless for days, unnoticed by its victims, an unseen herald of approaching disaster.