Tyranids

The Tyranids are an all-consuming alien swarm from beyond the known galaxy. Driven by the vast and ineffable intellect of the Hive Mind, their tendrils drive into fresh systems with every passing hour. These single-minded metapredators cannot be reasoned with, bought off, or put to flight. They seek only to strip each new world they encounter, devouring every shred of biomass to feed the relentless advance of the hive fleets and leaving dead, airless husks in their wake.