Destroyah

Destroyah (alternatively spelled as Destoroyah) is a colony of anaerobic Precambrian era crustaceans that were heavily mutated after a weapon known as the Oxygen Destroyer- a dangerous chemical that breaks apart oxygen molecules and causes organic matter to die or to disintegrate completely- was detonated to kill a monster named Godzilla in Tokyo Bay. Rather than dying to it, the colony adapted to the substance and incorporated it into their biology, forming a hive mind of deadly creatures. After 40 years of mutating, the colony surfaced and wreaked havoc across Tokyo until it presumably died.

EARLY LIFE Lying undisturbed since the Precambrian era, an unidentified species of microscopic crab lived deep underwater in modern day Tokyo Bay. These anaerobic creatures peacefully sustained themselves by feeding on the carcasses of dead animals that sank to the bottom of the bay. This way of life was interrupted in 1954 when a kaiju came to rest deep underwater after being awakened and rampaged across the surface. As the monster slept, a man was sent down there to detonate a deadly weapon designed to kill the kaiju. As the weapon went off, it woke the monster and killed it before it could escape- leaving nothing but a skeleton behind. Over the coming decades, constant exposure to the deadly substance mutated the colony.