Metal Gear Solid: Peace Walker/Weapons

Mk.22 Mod.0 (Hush Puppy)
The Mk.22 fires rounds that damage Psyche and put the target to sleep. After shooting an enemy soldier anywhere on his body, he will fall asleep after a delay. The closer to the chest or head you shoot, the faster the sleep effect procs. A headshot is immediately effective, though enemies will start wearing helmets as early as the mission Destroy the Barricade. Shooting an enemy soldier in his butt will also immediately put him to sleep. All iterations of the Mk.22 are fitted with a suppressor which will wear out after a number of shots. Only suppressed shots have the high Camo Index; once the suppressor wears out, Mk.22 shots will alert the enemy to your presence. The Mk.22 is CQC-compatible.