5907f556_ecrets_for_Xbox_360___GameFAQs__How_to_Unlock
[Unlockable] Moss Camo [How to Unlock] 
Defeat The End by sneaking up behind him during battle and pointing a gun at him. He will lay on the ground. Point the gun at his head three times, aiming elsewhere when he speaks.
Metal Gear Solid HD Collection Cheats, Codes, and Secrets for Xbox 360 - GameFAQs