Successfully complete the indicated task to unlock the corresponding
Avatar Award:

Bull Shifters Shirt: Win ten games of Versus.
Depeche Mode Shirt: Rescue Gnome Chompski from the Dark Carnival.
Left 4 Dead 2 Shirt: Win ten games of Scavenge.
Med Kit: Successfully complete all five campaigns.
Zombie Hand Shirt: Kill 10,000 Infected.