Using the Iron Man designs that Obadiah Stane acquired, he built the massive Iron Monger mech suit. It was first used to demolish a condemned building to make room for a new Stark manufacturing plant. O'Brian was the pilot for the mech, but he stops when he sees Iron Man holding a civilian, despite Obadiah's orders. Obadiah pilots the suit and continues demolishing the building, even though that old man came back to the building, passing him off as "collateral damage". Iron Man and War Machine try to stop him to no avail, until they realize that the suit needs outside computer control to ease operation of the complicated systems. Using a radio interference device, the Iron Monger's computer connection was severed and it tipped over when the armored heroes blasted it's leg.
The Iron Monger has been upgraded with an adamantium/vibranium alloy plating. Thanks to the mecha, Stark International has signed the biggest military contract in the world, eclipsing Hammer Multinational. Their board of directors almost made him the permanent CEO until Tony Stark presented them footage of his dealings with the Ghost. As a result, Stane was fired. Because of a similar phrase that both Tony and earlier, Iron Man said, Stane deduced his true identity. Wanting revenge, Stane stole the Iron Monger to go after him, unaware that Titanium Man put a remote control device on it. He kidnapped Pepper Potts to lure him out. Iron Man appears in the Hulkbuster Armor and War Machine saved Pepper. Stane had Iron Man at his mercy, but let him go after pleading from Whitney Titanium Man activated the remote control unit and sent it on a rampage, so he could be a hero by stopping him, winning Hammer Multinational the military contract. Stane breaks the mecha's controls and the Iron Monger falls onto the street and as a result, Stane was put in a coma.
The Iron Monger is a 30-foot tall, powerful, robotic mecha. Stane mentioned it had Hulkbuster armor tech inside of it. It could destroy military vehicles, the third unmanned Crimson Dynamo unit in one stroke, easily overpower Titanium Man, and hold its own against the Hulkbuster Armor.
- Enhanced Strength: The armor could strike down Iron Man with one punch.
- Enhanced Durability: It is impervious to attacks. It was unaffected when War Machine delivered its most powerful attack, something that at least Doctor Doom flinched at. It has been modified with an adamantium/vibranium armor plating, strengthening its massive damage resistance.
- Flight: It is equipped with jet boots in the feet.
- Weapons: It is featured with the following weapons:
- Laser Cannons: It has laser cannons in the arms and right shoulder that could knock back both Iron Man and War Machine even with their force fields up.
- Rocket Launcher: It has a rocket launcher on the left shoulder.
- Gatling Guns: The Iron Monger has powerful Gatling guns in both of its arms.
- Vibrational Shockwave: It can deliver a big shock wave of repulsor energy from its foot by stomping it on the ground.
- Hologram Projector: It can project the face of the pilot in the center that can speak to people on the outside. It can also speak to people on the outside without the projector.
- It has a radio transmitter to speak to the person on the other end.
- It is mentioned to have an eject function.
- Even though the Iron Monger is practically unstoppable, it's controls are too complicated to operate alone. It needs an outside link to a computer system so the pilot could control it more easily. By severing this connection, the Iron Monger is practically rendered useless. In Heavy Mettle, Stane was controlling the mech by himself, so its implied that this flaw has been removed.
- Because of its massive size and weight, it can topple when one aims for the legs.
- It isn't protected against Iron Man's Extremis.
- Stane said that the Iron Monger costs 80 million per unit to build.