Beasts

From back cover of Bantam paperback June 1978:

Half-human outlaws of a savage future America has been destroyed by civil war. Violent bands of barbarians and anarchists battle agents from the Union for Social Engineering, who plan to seize total control. But they are all united by their fierce hatred of the leos. Every hand s raised against the half-human, hal-animal mutants who roam the desolate frontier. The last, predatory creatures men call Beasts