The Crusher

The Enforcer is a Tier 2 Special Infected.

Appearance
Enforcers have the appearance of a large, powerfully-built military officer, still clothed in full company uniform. The most prominent of the "new" Infected, the Enforcer has a pair of bright, blue eyes, and a very hulking physique. Viral alterations have made the Enforcer much larger than most Infected, and its muscles have prominently increased in size. You can literally see the blue muscle-tissue bulging across its body, with white sinew lacing in-between the veins. The Enforcer also has red blood splattered all over its torso, which may have been his prior to Infection, or simply that of a victim it killed. Its bloody jaws are constantly bared towards its enemies, which could be a symptom of lockjaw. Because of their obvious characteristics, Enforcers can easily be distinquished from the other Infected.

How-to-Kill
Enforcers have pretty much no weaknesses at all, and there is no OHKO option for them. Your best option is to always aim for the head, fire everything you've got, and use plenty of explosives to weaken it.

Trivia

 * The Enforcer is loosely based on the Tank from the L4D series.
 * The Enforcer also shares a similarity with Relinquished, in character scheme and coloring. The mouth on its hand also bears a resemblance to T-ER's jaws.
 * The Enforcer apparently has a mouth in the palm of its right hand. This is hard to confirm, because the Enforcer doesn't use it in-game. It is unknown if the same thing applies to the left hand, and if the mouth has a purpose. It is speculated to have an HP-draining ability, though this is unlikely.