Exocrines

An Exocrine is a large Tyranid creature bred for long range fire support. Little more than a living artillery platform, the Exocrine is controlled by the brain of its Bio-Plasmic Cannon Biomorph, a giant weapon able to unleash a vast ball of plasma, or several focussed streams of fire from its multiple barrels. The Exocrine itself is purely a means of transportation for the bio-plasmic cannon nested into its flesh. Only when the larger beast remains still can the symbiote focus all of its mental resources into targeting and destroying its prey. Because of their ability to deliver powerful long-ranged firepower, Exocrines are perhaps the most feared gun-beast in the Tyranid swarms.