Intially, mutants living on the island of New Guinea. Their deformities are a result of the atomic dust cloud plaguing the large island. Incredibly fierce and agile, the New Guinea mutants have resorted to cannibalism. They devoure other humans who happen to stray into their area. Hunting in packs, the mutants will climb nearby trees and leap down upon their prey to ensure the element of surprise.

While the mutated inhabitants of New Guinea were a real threat, this concept is expanded upon as Ryougen Nishiyama warns of the possible consequences that could continue at Earth's current rate. Nishiyama's predictions include a scenario where the world would be almost completely decimated following the end of World War III. With nuclear bombs being exchanged between the global powers during the warfare, the Earth would be left a barren wasteland. Yet, from the extreme levels of radiation and the ruined lands, life would find a way. Through these hardships, humanity continued, yet only a horribly grotesque visage of what the proud race once looked like would survive. Digging small burrows in the ground, these even more heavily mutated humans would emerge to venture through the desert-like terrain only when seeking food. However, very few species escaped the cataclysmic events of that devastating war. Of those that did survive was a small species of snake, which became the diet of the mutants.