Guilala
Region of origin: The depths of space
A massive creature born of a fungal or plant-like spore, the guilala feeds on energy to increase its mass, abilities or reproduction rate. The guilala was weaponized by an unknown alien race, who sprayed a human vessel that was attempting to approach Mars with the spores; as the humans returned to Earth one spore that was brought back for research was broken out of containment in an accident and grew to a gigantic size, rampaging through cities in a search for more energy to consume, shrugging off any artillery and other military intervention it encountered. From a casing that originally housed the spore, human scientists involved in the Mars missions were able to synthesize a material, named Guilalium after the monster, that they coated the creature with and was able to block its energy absorption and, starving it, reduced it back down to its original dormant state, which was then sealed away and launched back into space.