Hive fleets drift silently through the stars, seeking their latest planet-sized meal as they incubate a vast horde of Tyranid broods within them. When a target is identified, they begin to launch spores full of bioforms at the planet to subjugate its defenders. When encountering particularly tough prey, the Hive Mind will unleash a horde of its largest monsters to utterly annihilate them – a collection of creatures referred to by distraught survivors as a Crusher Stampede.

A Neurotyrant with two Neuroloids provides a synaptic core for this bestial menagerie. The Screamer-Killer – so called for the earsplitting shriek it makes as it hurls gouts of burning bio-plasma – leads the charge, accompanied by a Tyrannofex, which carries a huge living weapon, an unfathomably ravenous Haruspex, and a Maleceptor, which obliterates foes with powerful psychic energy blasts. These monsters also have alternative builds: the Tyrannofex can be built as a Termagant-birthing Tervigon, the Haruspex as a sentient artillery piece known as an Exocrine, and the Maleceptor as a miasma-generating Toxicrene.