Fireaxe

The Axe is a melee weapon featured in Left 4 Dead 2. Nothing is known about it at the moment except that it kills special infected (except The Tank And The Witch) in one hit. It is obviously a slashing weapon, and as such can sever limbs.

Trivia

 * It seems to gather blood as it is used more. It starts as a normal looking red fire axe, but after a fair amount of usage, it shines with splattered blood.