The final antagonist and true leader of Outer Heaven. This is the ultimate test of your combat skills.

- Location: A confined room after Metal Gear's destruction.
- Attack Pattern: Big Boss is armed with a powerful machine gun and moves quickly around the room, firing continuous bursts. He will try to corner you.
- Weakness: The Rocket Launcher is the most effective weapon.
- Strategy: This is a direct combat encounter. Equip your Rocket Launcher. Big Boss has a large health pool, so you'll need multiple hits. Dodge his machine gun fire by constantly moving around the room. Try to get a clear shot with the Rocket Launcher when he pauses or is moving predictably. If you run out of rockets, the Submachine Gun is your next best option, but it will be a much longer and more difficult fight. Use Rations liberally to stay alive. This is a battle of attrition and precise aiming.
- Reward: Completion of the game and the true ending.
Ensure you have a good stock of Rations and as many Rocket Launcher rounds as possible for this final showdown. It's a challenging fight that demands your full attention.