The Tyranids version of Star Wars General Grievous. The ultimate creation and guiding intelligent commander. It is one of those Tyranids that can't die and can bring itself back to life to another Tyranid Warship should it perish in battle.
The Swarmlord is a uniquely powerful Tyranid biomorph. Amongst the billions of creatures created by the Tyranid Hive Mind, there exists one as old as the Tyranid race itself, the ultimate
conduit through which the Hive Mind's implacable will is enforced. This creature is to a Hive Tyrant what a Hive Tyrant is to a Termagant. It is a monster of darkest nightmare that has preyed on empires and overseen the extinction of entire civilizations. It is a legendary destroyer of world and its names are legion. It is the Tyrantlord of the Hive Mind, the Herald of the Great Devourer and the Destroyer of the Kha'la Empire. To the Imperium of Man, the latest interstellar civilization to face this ancient predator, it is the Swarmlord, and it represents the greatest Tyranid threat to the galaxy. The Swarmlord is the pinnacle of the evolution of the Hive Tyrant bioform, a truly unique monster. The Swarmlord is essentially immortal, like a Hive Tyrant, as once killed it is reborn by the Hive Mind with the exact same experiences, character and knowledge, in essence becoming stronger than its predecessor every time because of its new experience. But unlike a Hive Tyrant, the reincarnation of the Swarmlord appears to be a stress induced response that is triggered only when conventional strategies of the Hive Mind fail and greater resourcefulness and tactics are needed. To this end, the Swarmlord possesses more autonomy from the Hive Mind than any other Tyranid creature, and its connection with the Hive Mind is so strong it can emerge amongst any Hive Fleet, transcending any physical limitations separating the different Fleets. The Swarmlord has aeons of battle experience and bloodshed to draw upon. As weapons the Swarmlord wields four bone sabres, crackling with disruptive power, that are capable of slicing through adamantium and force fields as if they were nothing. They differ from commonly seen Tyranid Boneswords in that each sabre has a crystalline growth, not indigenous to the galaxy, at its core that partially protrudes through the blade's serrated surface. The Swarmlord can parry with these sabres at such speed that its foes find it all but impossible to inflict a hit on the creature.