UOA-IIs or "Metal Gears" are huge bipedal machines armed with a 19.2mm rotary railgun and a flamethrower. They can replicate ammunition by consuming organic matter and scrap metal, granting them incomparable combat autonomy. Xenoanthropologists theorise that the UOA-II was specifically built as a heavy combat unit, first responders against the biological horrors of the Ents around Precursor settlements. Metal Gears will always leave behind a trail of death, confusing mankind for its eternal enemy. Curiously, these robotic entities seem to “play” when left alone for long periods of time by smashing rocks together or chasing wildlife like a child would, suggesting that their central processing unit contains a crude artificial general intelligence. Their motor and logic systems are more rugged than that of the UOA-Is, and they possess plasteel armour capable of withstanding modern tank fire from up front. UOA-IIs are powered by a miniaturised fusion reactor whose workings remain an enigma.
Being a "heavy" type of combat robot designed to fight the mutated surface, even after the Precursors' extinction, they are produced en masse within Black Factories.