Special infected are a faction of 8 infected with special abilities. they are the biggest threat to the survivors in Left 4 Dead and Left 4 Dead 2. It takes time for them to reuse their primary attack, except The Tank and The Witch because they can use their melee attack anytime. Like normal infected they cannot open doors, and must break though them. 7 of them are playable in "versus", each have their own "music cues" and "noises" to warn the survivors that they're around.
There are 8 special infected, 7 of them are playable.
The Tank - The strongest out of the 8 special infected, the biggest threat to survivors and can kill a group of survivors unless they team up. He is big, strong, and fast, though healthy survivors can outrun him. He is able to hit survivors from far away with rocks which he can take from the ground.
The Witch - The second strongest out of the 8 and is the only female special infected in Left 4 Dead while one of the three female special infected in Left 4 Dead 2. When around, the players can hear her cry. Survivors can sneak past the witch. The loudness of her growl will predict when she's close to attacking. She'll attack whomever "startles her" and retreats if that person is dead, She is the only non-playable special infected in versus mode.
The Boomer - The Ambusher of the infected., he is obese and slow. There is the male boomer in Left 4 Dead 1 and the male and female boomer in Left 4 Dead 2. The primary attack of the Boomer is puking, blinding any survivors hit by the bile, and attracts common infected, only attacking that person/people. When a Boomer is killed, he/she explodes, splattering vomit. A new weapon called "Boomer Bile" appears in Left 4 Dead 2, which attracts Common Infecteds, and attacks any infected that are covered in it.
The Smoker - The Infected who prefers long distance. He is tall, thin, and has smoke around him, The smoker has a whip-like tongue, which he use as a primary weapon. He is capable of dragging a survivor at least 80 feet. He is not really strong when it comes to physical strengh and retreats if his victim is free. When killed, he release a small cloud of smoke, making it hard for the survivors to see.
The Hunter - The Infected with the big jump, He wears a hoodie and only half of his face is shown. Out of all the 8 special infected, he looks the most like a common infected. His primary attack is pouncing. When he pounces, he will attack his victim until he is shoved off, or he/the victim is dead. He has sharp claws which deals alot of damage. He needs to be crouching to pounce, which causes him to growl, but while standing up he remains silent.
The Spitter - The acid spitter. She has a long neck. Due to her mutation, she is able to spit acid. This causes her to be slow for a few seconds. She walks weirdly and makes faint squeling sounds. Her purpose is to slow down or split the survivors. When she is killed, she releases a small patch of acid.
The Jockey - The smallest and nimblest. He has a hunchback look, He laughs maniacally, he will only stop when he is killed. The skin around his mouth is ripped off. He lunges onto survivors and controls them, but the survivor is able to fight back.
The Charger - The one with the big arm. He has a hillbilly like apperance. He has one big arm which he use as a weapon to charge at survivors and pummel the first survivor he hits. His other arm is small and useless. He is the second largest of the 8 special infected. He has the third highest health at 600. The punch of the Charger does 10 damage per hit and he is immune to shoves. He makes human like speech when around.