In our future, an ecological disaster has destroyed most life on earth. Humans are infertile. The last gasp of humanity is a small group of men who have control over a cloning laboratory and its staff. The staff decide to mix reptile DNA with the human, because a lizard is able to regenerate body parts. Lizard men are the result. They are cloned in cocoons that they must punch through to hatch. After they break through the cocoons, they roam over the dregs of the world. Why only lizard men? Since humans are infertile, in the minds of the men in control cloning women is unnecessary.