The Charger, an infected with an enormously mutated right arm, can charge into the survivors and seize and separate one survivor from the others while pummeling them in to the ground the survivor is helpless until one of their teammates helps them.
The Spittercan project balls of stomach acid that splatter across an area, quickly eroding the survivors' health as long as they remain within it and the longer they stay in it the faster their health drops.
The Jockey can jump onto the back of a survivor and steer them into other infected or terrain traps while scratching up their face.
The Boomer is a bloated infected that can spit vision-impairing bile on the Survivors that attract hordes of infected, and explodes on death, spewing more bile in the immediate area.
The Hunter is an agile foe that can jump and pounce on a Survivor, and then tear at his victim until he is knocked off or killed.
The Smoker has a long tongue that he can use to ensnare a Survivor and then drag him back to himself, either attacking the Survivor directly, allowing the horde to attack the Survivor, or leaving the Survivor suspended over a cliff or roof edge; the Smoker only releases its victim if the tongue is shot or on death, at which point it dies in a burst of vision-clouding smoke for a brief period.
The Tank is a gigantic muscular infected that has the ability to swipe at Survivors, knocking them off their feet and incapacitating them; it can also knock cars and other debris into the Survivors.
The Witch is a passive female infected that stays in a spot, crying; Survivors can sneak by the Witch, but if they should disturb her with light or loud noises, she will become aggressive and attack the Survivor that alerted her, usually incapacitating the Survivor and attacking him until she or the Survivor is killed.
Each of these special infected is preluded to players through special audio cues; for example, the Witch's cries or the Smoker's coughs can be heard before they are seen, while certain musical cues will alert the players to the presence of a Hunter in the area.
One special infected did not make it into the game. The "Screamer" was an infected strapped in a straitjacket and let out a loud, high-pitched scream when it sighted the survivors, thus forcing the survivors to find and kill it before it screamed, resulting in a horde of common infected. However, it ended up being too difficult for players to figure out where the Screamer came from or where it was going or even understand that they were meant to chase it. Because of the confusion, it was replaced by the Boomer.
I prefer the Smoker because it needs to hide up on the obstacles such as houses or in a well-hidden place somewhere, wich I really like.. Because I like going Ninja.. ;-)
