The Walkers' appearance is considered to be quite monstrous and grotesque, resembling the Blair-Thing's own appearance. They possess two large claws on both arms and large spider-like legs, and have a human torso attached to their body, presumably the host. Some early forms of Walkers possess two arms with sharp claws and two legs.
Walkers are considerably large, which makes them have a strong melee attack. It's best to mostly stay away from them and reduce their health from afar. The best weapons to use against them are the Shotgun and the Machine Gun. Since they are second stage Things, the only way to kill these monstrosities is by incinerating them with a flamethrower, blowtorch or flame grenade after weakening them with gunfire.
The Brute Walker is considered to be the first form of the Walker. Its appearance is quite brutish, but despite its physical form it possesses remarkable speed and can grow into enormous forms. They are endowed with sharp claws on each arm and don't seem to possess any visible eyes or mouth. They are also capable of producing Scuttlers.
This Walker form is considered to be the form of a fully transformed Walker, although they still have some traits of their early form; they have extended claws and arachnid-like legs, and the tails they drag behind them are actually armless human torsos. Once enough damage is dealt to them, they have a special transformation where a head with a visible mouth with sharp teeth emerges from its split head. This head grants them a special attack, where they lunge forward and bite, dealing nearly one quarter in damage of the whole health bar.
A rare form of the Walker. Not to be mistaken with the Dog Beast. Its appearance is quite similar to that of an ordinary Walker except for its head, which resembles a dog. Unfortunately, the "Cerberus" variant with three heads shown in the picture below appears only in the beta version of the game (notice the clothes Blake is wearing, the correct MP5 model for the Machine Gun and also the fact that in the Strata Medical Facility there are only one regular and three brute walkers). However, one different Dog Walker with a single dog-like head appears in the Strata Furnace facility.