In their seed forms, likely all that will ever be seen, Summer’s Extinguisher is a large, black egg of a strange, iridescent material, nearly half a mile in diameter.
Mature, the Extinguisher is no different in appearance from any other volcano, though a quick check of its composition and position will almost invariably show its nature.
Consisting, primarily, of a colony of thermally resistant fungus spores, Summer’s Extinguisher’s fills but a single purpose. It burrows into the crust of the world, mostly of the mass carried, but also using the silicon and carbon it finds as it burrows to expand its numbers, until it pierces the crust of the world. A channel thus opened, it unleashes hot magma, while filling the sky with vast amounts of smoke and ash, even as it filters away carbon released thusly.
Employed in numbers, even though it breeds itself, unleashing seeds to float through the magma, Summer’s Extinguisher quickly denies the world beneath it the light of the sun above, plunging the planet into an abominable winter, too cold for all but the very heartiest of simple life, and the most determined of sentient life to survive for long. Usually, the world is dead within months of initial bombardment, newly pockmarked with hundreds of new super-volcanoes. It is also possible for the entire crust to be fractured in this manner, leaving a twisted land of earthquakes, heated from below and frozen from above. It will progress towards a cyclic consumption of the crust, replaced from the mantle beneath, until the counter-phages1 to turn the weapon ‘off’ are deployed, each unique to a given set of weapons.
Short of the phages, only determined physical uprooting of the spores can remove them from the crust of the planet, a difficult task indeed.
Carefully applied, this creature can also be used as a potent terra-forming tool.
Due Acknowledgement: Mycon Deep Children - http://uqm.stack.nl/wiki/Deep_Children
1: bacteriophage - A virus that is specialized in the invasion and destruction of bacterial cells. Generically, a bio-engineered phage can theoretically be used to destroy any given specific kind of cell.