During the Human/Covenant War, the Springhill class mining vessel known as the CAA Heavy Burden was heavily damaged, and forced into a decaying orbit around a gas giant. The automated systems on board the ship continued to function as the orbit decayed, and the ship was eventually destroyed. However, the CAA Heavy Burden's schematics were uploaded into the UNSC Infinity's computer systems for use in War Games simulations. In these simulations, this mechanical giant is under construction. Not much is known about the HRUNTING/YGGDRASIL Mark II [D] Armor Defense System, other than its similarities to the smaller and more modern HRUNTING/YGGDRASIL Mark IX "Mantis" Armor Defense System. Due to these similarities, this UNSC mech is nicknamed the Mega Mantis. The Mark II [J], a well known successor to this mech, is commonly called the Colossus.

Controls:

• Throttle: Walk Forward

• Yaw: Steer left/right

• VTOL: Raise/Lower Arms

• Trim: Rotate Torso Left/Right

• AG1: Toggle Chaingun

• AG2: Toggle Anvil III Missile Launcher

• FireGuns: Overload Hydraulics