Races whose primary thing is to consume and assimilate all organic life (or even everything in general)
1: The Zerg (Starcraft) 2: The Tyranids (Warhammer 40k) 3: The Gauna (Knights of Sidonia)
1: The Zerg (Starcraft) 2: The Tyranids (Warhammer 40k) 3: The Gauna (Knights of Sidonia)