The Lictor is the swarm's silent herald, a specialised evolution of the Tyranid Warrior grown for infiltration rather than open slaughter. Its carapace shifts colour to match whatever surrounds it, rendering the creature all but invisible, and it moves through the densest terrain in absolute silence, capable of crouching motionless for days on end while its prey passes within arm's reach and never suspects a thing.
When it strikes, it does so to kill and to learn. Feeder tendrils that ring its maw allow the Lictor to consume a victim's brain and digest the memories held within, and from that grim feast it gleans the disposition of an enemy's forces, the routes into their strongholds, the weak points in their lines. It hunts scouts, sentries and lone stragglers, unravelling a defence one silent death at a time.
Most insidiously, a Lictor operates free of the synaptic web that governs lesser bioforms, needing no Warrior or Tyrant nearby to direct it. As it kills, it exudes a pheromone trail that acts as a beacon to the wider swarm, drawing the ravening broods unerringly toward the richest concentrations of prey. Where a Lictor has walked, the full horror of the hive fleet is never far behind.