The origin of these violent, manic creatures is not entirely known, but they exist for one obvious purpose: having a heavy-duty motorized saw for a face. They feed by "drinking" organic matter as they pulverize it with their blades, and retain inorganic matter to produce young with fully-formed saws of their own. The average chainsaw kid can generate and lay a single egg every three to four years, and the kiwi-like hatchling grows rapidly the more it feeds. These "feral" Kids are skinless except for their bony masks, and cannot abide the touch of direct sunlight. When created fresh in the lab, Chainsaw Kids are usually provided with a leathery wrapping or patchwork skin.

These monsters are of human intelligence, but only speak in buzzes, honks, squawks and syllables comprising the word "chainsaw". Using their saw is their answer to virtually any dilemma, including riddles and hypothetical questions. They are terrified of cats for no known reason.