The Becca Mold

In 2074, Arasaka developed a bio weapon that, in theory, turn dead people into fully alive super weapons. this weapon was a type of mold that grows throughout an entire ecosystem and infects any dead organisms, including humans. it enters through the mouth or nose and immediately deploys stem-cell-like fungus enzymes that repair all damaged cells in the creature's body. it then takes over it's brain and modifies the creature's physiology and replaces most of it's skin with a transparent memebrane, so it can transmit the spores easier. the mold slowly rebuilds the structure to make the creature taller and larger. all fat layers are consumed by the mold and repurposed to build out the hex lattice bone structure. the end product is a horrific, boney monsterous being that works as a mindless kill drone for the mold hive mind