Most noteably found on Battlefield Bad Company 2, the Bush Wookiee is a player who constantly hides in the bushes and never goes out into the real fight. They will always take pot-shots from the bushes, and slowly make their way around a main base like some kind of hostile native. Basically, they hide in the jungle like the wookiees on Star Wars, hence the name.
You can see them running around in the brush, and may even aim at them, but you will believe that your eyes are playing tricks on you until they blow your brains out. The Wookiee's mortal enemy is the spot button.

when you're hungover as shit after a spending a night drunk as a skunk