Voracious Serpent

While hiding inside an upgraded cardboard box, perform a stealth kill. (Score +400)

You will drag the enemy's body inside the box, successfully concealing it. However, upon moving you will leave the box behind with the body inside.

You can retrieve the box, however the body will then be exposed.

Trivia

 * The name of the achievement earned for doing this, Inner Heaven, is a reference to the Metal Gear Solid series, where the use of cardboard boxes for stealth purposes plays a prominent role