That’s what these creatures are.
They swell the now blackened streets of a former epoch, slithering and sliming, feeding and breeding like skinned and glossy rabbits.
On a day not too long ago, after the civilization of Man had come to know the only tidbit of peace it would ever have the chance to appreciate, the beginning of their end manifested itself as a sideways glance into a mirror and the diagnosis of what they considered to be their biggest folly. This is what humanity did: Only after they put down their bows and arrows, their guns and their bombs and held each others hands in brotherly solace did they turn their selfish eyes to their conceiver, their mother Earth.
For centuries the ignorant species suckled upon the bountiful teat of Gaia, only to disgorge their sustenance back into her lungs as polluted smoke and detritus. With eyes now clear they could see this, and through their overconfidence they surmised a world-wide, collaborative project to “clean the skies”; to rid the world of its poison as they saw it: physical pollution. But mother earth had only but one pollutant: the human plague.
They—in truth—supplied the vaccine. They, who thought of themselves as beings of altruism, saviors to a being they could never possibly understand or truly know, helped in a way similar to a tapeworm feeding its host. On that day when the missiles struck the atmosphere, they watched. The skies lit up with little supernovas, a fourth of July to remember their past wrongs and their present benevolence. Then, as the pretty fireworks display fizzled away, they set their heads down to rest like babes in a mothers nest.
The killing rains came quickly and without warning. It was as if the planet was weeping. Only, the black tears of their Mother were not from pain. Once more they entered a dark and lightless age; they were consumed into a death womb. Mankind died, and changed; once they had been warm blooded, but not anymore.
A new strain for a new host.
The rains never stopped, cleansing the flesh of the Earth.