A Genestealer Patriarch is the massive Tyranid Genestealer bioform who is the original vector that created a Genestealer Cult on an infested world and becomes its leader and the ultimate controller of its Broodmind.
Lurking at the centre of a Genestealer Cult's web of lies is the Patriarch, father of a hidden dynasty. Twice the height of a Space Marine and with strength enough to slice an Ogryn into bloody chunks, this creature is a leering nightmare of tooth and claw.
In a flurry of whipping limbs and diamond-hard talons the Patriarch can tear through platoons of heavily armoured warriors and even light vehicles.
Yet it is the hypnotic psychic spell with which it binds its chosen hosts that mark it out as perhaps the most dangerous Tyranid yet encountered by the Imperium.
The uncanny powers of the Patriarch make it a fearsome puppet master, a threat so pervasive it has an Imperial xenocode threat designation unto itself. By spreading the Genestealer Curse, this creature is capable of destroying not just warriors and war machines, but entire worlds.