There are eight types special infected, seven of them are playable. Seven of them are playable in 'versus', each have their own 'music cues' and 'noises' to warn the survivors that they're around.

Like normal infected they cannot open doors, and must break through them. It takes time for them to reuse their primary attack, except The Tank and The Witch because they can use their melee attack anytime. they are the biggest threat to the survivors in Left 4 Dead and Left 4 Dead 2. The Special Infected are a group of eight types of Infected with special abilities.