In the vast universe, apart from earth-shattering wars between civilizations, there is another kind of conflict that can be described as utterly ruthless.
When civilizations clash, even the defeated have the option of surrendering, at worst being reduced to a vassal civilization.
However, this special type of war leaves no room for compromise; it is strictly a matter of life and death—either achieve ultimate victory or face total annihilation. Such a desperate struggle is the war between civilizations and fierce beasts (also known as star beasts or the Zerg). What they are called does not matter; the crucial point is that these beasts or the Zerg are born as killing machines.
Chapter 172