This is how it works:
step 1. Point it at an enemy.
step 2. Press and hold the shoot button (Rt for 360/ R1 for PS3/ Mouse click for PC) for a few seconds and the weapon will svck the enemy's skull out of his head and it will load into the weapon as ammo!
step 3. Point your weapon at a new enemy.
step 4. Press the shoot button and the weapon will shoot the skull with high power at the enemy!
This weapon is handy when you've no ammo left, but the weapon will break fast (otherwise it will make the game unbalanced because fallout must be a struggle imo).
Please post what you think of my idea and post your creative and innovative weapon ideas! (Not a gun that shoots cows...)
Thx!
Edit:
I't looks like a high tech vacuum cleaner with a scope on it!