Lictor

 Tyranid Lictors are specialised evolutions of the Tyranid Warrior, suited to scouting and assassination. Lictors move ahead of the main swarm, seeking out pockets of resistance and native life forms to be eradicated or 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.