Ironclad is a mobile fortress — a squat, massively armored platform that moves on eight short, wide legs like an enormous mechanical crab. Its profile is low compared to other Behemoths, standing only six stories tall, but it stretches over 80 meters long and 50 meters wide. The surface is covered in overlapping armor plates of varying age and origin, some clearly scavenged from other machines, buildings, and vehicles. Ironclad has been adding to its own armor for decades, welding new layers onto itself from whatever it encounters.

The machine's interior — glimpsed through rare breaches in its ever-thickening shell — appears to be a vast manufacturing space where robotic arms strip salvage and integrate it into the hull. Ironclad actively seeks out wreckage, ruins, and abandoned infrastructure, pausing over them for days while extending articulated crane-arms to harvest material. It has been observed dismantling entire highway overpasses, pulling rebar and concrete into itself and emerging slightly larger, slightly heavier, slightly more armored than before.

What makes Ironclad particularly terrifying is that it is the only Behemoth confirmed to respond to aggression with deliberate, targeted force. In 2180, a mercenary company hired by Tessera Dynamics attempted to breach its hull with shaped charges. Ironclad sealed the breach within minutes and then spent three days systematically hunting the mercenary team across forty kilometers of wasteland, crushing their vehicles and equipment with precise leg strikes. There were no survivors. Since that incident, a standing advisory warns all corporate and independent forces: do not engage Ironclad.