of all the beasts of the tyranid swarm, the norn queen is perhaps the most interesting, she is the progenitor and master geneticist of the swarm fleet, a being created to only feed on biomass and create new and more effective tyranids to fight and consume everything at his step

This being is working with its biomass, molding, perfecting, traveling paths that the genetic code would not have taken, all to create more effective "children"