The Standard Infected
The Infected (sometimes referred to simply as Zombies by the survivors) are Tek Industries Research Team take on the classic movie and pop-fiction zombie. Rather than being undead, they are living humans who have been Infected by the Green Flu virus, causing massively increased aggression and loss of many higher brain functions such as speech and self-preservation. Like cinematic zombies, those present in the Tek Industries Research Team series attack human victims until they themselves perish or kill their target.
Tek Industries Research Team researched seven special types of Common Infected known as "Uncommon Infected". Each Uncommon Infected is unique and has its own special ability that makes it slightly to moderately more dangerous than Common Infected. .
Seven of the Special Infected are playable by human players in the following gameplay modes: .
Boomer
The Boomer is a Special Infected that vomits a special bile at Survivors, which temporarily blinds them and draws a Horde of Common Infected to them. At a distance the Boomer isn't much of a threat; their large size and low health make them an easy target against any weapon at mid or long range. However, if within range, they can vomit on Survivors, attracting the Horde. .
When they die, they explode, covering any Survivors who are close enough with bile, blinding them and causing them to stumble backwards. The Boomer is notorious on the Expert difficulty for being able to snipe Survivors. Boomers can be anticipated because of the near-constant gurgling they make. In Tek Industries Research Team , there is also a female Boomer, although the gender has no effect on gameplay. .
The Hunter
.The Hunter is a Special Infected that has the least visible mutations, and can be mistaken for a Common Infected. The Hunter is absurdly fast and agile, capable of quickly scaling walls. Additionally, he can pounce and pin down Survivors, clawing at their abdomen until either the victim is dead or the Hunter has been knocked off or killed by another Survivor. Hunters are not the most physically robust Infected, having relatively low health, and thus it doesn't take very much to kill them. .
When the Hunter crouches down in preparation to pounce, he growls, giving himself away to any nearby Survivors. However, whilst standing, he makes no noise. The Hunter is the only Special Infected that can remain absolutely silent. In Tek Industries Research Team , they can be killed with a melee weapon while in the state of pouncing by aiming upwards and hitting, although this is fairly difficult, as timing is vital and it's easier to kill them from a distance with a high-powered primary weapon. .
The Smoker
.The Smoker is an ambush class that can strangle Survivors with their long tongue, similar to Half-Life's Barnacle. The help of another Survivor is required to escape from a Smoker's hold (There's a short delay before it starts to drag you, during which a shotgun blast may kill it in easy, and doing so successfully grants an achievement). As the name implies, Smokers emit smoke when killed to impair Survivors' vision. .
A Smoker also will frequently cough, letting the Survivors know when he is in the area. The Smoker can drag players that he has captured with his tongue towards himself, though he remains stationary and cannot move. The Smoker is also momentarily paralyzed for a few seconds after having his tongue removed from his captive by another Survivor. In Tek Industries Research Team , the Smoker has six tongues, the addition seems to be cosmetic. .
The Tank
The Tank is the biggest and strongest of all the Infected and is reasonably fast, only slowing if hit with large amounts of automatic weapons fire or when lit on fire.He is the only player-controllable "Boss Infected." If any Survivors at 40% or above health (including health gained from pain pills or the Adrenaline Shot) are running away from the Tank, it will not be able to catch them, as they can run slightly faster . .Nevertheless, the Tank will die within 30 to 45 seconds if set on fire (varying with the difficulty), except in Versus. When controlled by a player, the Tank has a "Control Meter"; unless the player is able to locate and hit one of the Survivors, the Control Meter of the Tank will slowly lessen, and once it runs out, the player will lose control of the Tank to another randomly assigned player or eventurally, an AI. When idle, the sound that a Tank makes is heavy breathing. The Survivors are alerted of an approaching Tank by dramatic music, furious roars and, when they are dangerously close, the screen will start to shake. .
The Charger
.The Charger is a Special Infected that is studdied in Tek Industries Research Team . The Charger's main attack is charging forward and plowing into the Survivors, hence the name. On a successful charge, he will grab and carry a single Survivor while knocking down the others. Once the Charger has hit a wall or other surface, or after he has run a certain distance, he will begin slamming his captive into the ground (and also into the wall and the ceiling if there is one) until an ally frees them. If he misses and hits a wall, he will stumble for a few seconds and becomes vulnerble. If a Charger smashes into anything when not grabbing a survivor, he takes 2 damage instead and is stumbled for 1 second. .
The Charger can be detected by the Survivors by the warped growling noise he makes. He will announce his charge with a loud bellow. The Charger appears to have a rocky or calloused surface on his larger right arm, which is what he uses to inflict most of his force when charging, while his other arm appears to have no bones or muscle, flopping around uselessly. .
The Spitter
The Spitter is a Special Infected. She possesses the ability to spit a green ball of acid from long distances, which, upon hitting the ground, will expand into a large puddle and damage any Survivors who make contact with it. After spitting, however, the Spitter is temporarily paralyzed for a second, giving the Survivors a chance to kill her. The Spitter makes these high-pitched noises that gives away her location.
The longer the Survivor stands in it, the more damage the Survivor takes from the goo. This ability allows the Spitter to aid other Special Infected; for instance, if a Hunter pounces a Survivor, a Spitter can spit upon that Survivor, causing even more damage. However, in spite of such a useful ability, the Spitter is very weak in terms of health, so taking out a Spitter is an easy task. .