A Genestealer Cult is a xenos-worshipping secret society made up of and controlled by Tyranid Genestealers that thrives in the dark corners of the Imperial underworld across the galaxy. Secretive, stealthy, and utterly malignant, Genestealer Cults are the cancers growing unseen in the hidden spaces of Mankind’s realm.
Their purpose is to rise up and take control of Imperial worlds in the name of a xenos god that is actually a Tyranid Hive Fleet. Once the world is under their control, the cultists’ psychic emanations are picked up by the closest Hive Fleet’s extension of the Hive Mind which is then drawn to consume the world, cultists and all.
Some cultists are truly monstrous, skulking along dank tunnels with robes or hessian sacks covering their hybrid xenos anatomies. Others are merely pallid and bald, able to pass for loyal Imperial citizens whilst their wyrm-form tattoos remain hidden.