Tyranids

The Tyranids are a fictional race from the Warhammer 40,000 tabletop game and its spin-off media. They are known to the Imperium generally as Tyranids, because Tyran is the first known planet they devoured and where they were first encountered. Luckily for the Imperium, Inquisitor Kryptman found oral data concealed on one of the databases on Tyran and dedicated the rest of his life to exterminating the new foe.

They are a nomadic alien race comprising many genetically engineered forms created from harvested bio-mass. They are known as the "Great Devourer" and also "Shadow In The Warp" (after the effect of their hive mind on FTL travel and communications) and pose a severe threat to the Imperium. They seek to consume all in their path, draining all planets of every resource and converting all living and some non-living material into Tyranid biomass.

They are said to be inspired by H. R. Giger's "exo-skeletal nightmares" in the Aliens films.