Beastmen are a "species" of humanoids that act as the primary antagonists for Parts I and II of the anime series Tengen Toppa Gurren-Lagann. They are the product of an ideal blending of human and animal genes, intentionally flawed hybrids with a human intelligence and form but great diversity in size, shape, and limbs. Their animal features can be almost anything: marine, amphibian, mammal, bird, or sometimes an entirely unrecognizable type of animal. Lordgenome originally engineered the Beastmen as soldiers against the Anti-Spirals, because the substitution of animal genes distorted the shape of human spiral DNA and rendered them invisible to detection. However, doing so came at the cost of evolutionary potential, for Beastmen lack Spiral Energy and thus cannot pilot Gunmen without the use of solar-powered batteries. Furthermore, their bodies deteriorate at an accelerated rate and their cell lines weaken overtime, thus forcing Lordgenome to deep freeze unborn specimens who are in a constant state of regeneration.