Hunter

The Hunter is one the cameo Monsters from the videogame Left 4 Dead that appears during the movie, along with the Boomer, Charger, Smoker, Tank and the Witch.

It was placed here because the directors originally planned to release Left 4 Dead exclusive DLC maps that featured the Cabin and the Facility. This idea was eventually scrapped when the company producing the DLC went bankrupt.

Physical Description and Attributes
The Hunter appears in a faded blue-hooded sweatshirt and dark brown sweatpants and black sneakers. His hood is always pulled down and over his face, which on close inspection, reveals that the skin around his eyes has either been clawed off or has become mutilated

as a result of the Green Flu, the type of zombie virus he suffers from in the game. The limbs of his outfit are battened down with duct tape.

Its possible a vile of Boomer Bile could be used to summon the Hunter from the Cabin's Cellar.

Appearances
The Hunter can be seen in a cube far above the cube where Marty and Dana reside during the pan out shot that reveals the assortment of monsters during their elevator descent into the depths of The Facility.