High Quality Content by WIKIPEDIA articles! In the fictional wargame Warhammer 40,000, the Tyranids are a nomadic alien race comprising many genetically engineered organisms that range greatly in size and purpose. They are many times referred to as "The Great Devourer", "The Shadow in the Warp", "The Doom of All Things", "Penance of the Elder Gods" and other equally dramatic names and are commonly said to be the "most alien race" in the galaxy where the game is set, since the Tyranid fleets started to pierce into the galaxy from the intergalactic void (which would suggest they traveled from another galaxy).