Set in a galaxy eternally at war, the Warhammer 40K universe is not short of grave alien threats for humanity to wrestle with. From the bloodthirsty Orks to the corrupting forces of Chaos and beyond, the Imperium of Man is beset on all sides, forced into a state of constant military engagement. However, there is one xenos race that represents existential doom for not only the Imperium but every sentient species in the Milky Way galaxy: the Tyranids.