Infected

The infected are humans who have been infected by the and subsequently mutated into horrific new forms. The resulting creatures are aggressive, and will attack any uninfected human and animals on sight.Infected infographic
The infected are one of the main enemy types in The Last of Us, Left Behind, and The Last of Us Part II, the other being non-infected human enemies.
== Overview ==
The infected are the result of a sudden outbreak of a mutant Cordyceps fungus that now affects human beings as opposed to insects. The fungus reportedly originated in South American crops; various newspapers in Austin in 2013 support this claim."Hometown" The fungus infects the human brain, growing mycelium inside the brain tissue and killing the brain's cells. This erases memories and drives the host insane, modifying their instincts to seek no goal other than spreading the spores to others. Eventually the fungus kills its host and then grows fungal tendrils out of the host's body to spread spores.
The fungus quickly became a worldwide pandemic, decimating the general population, creating panic and disorder. The initial infection caused the total breakdown and destruction of society, inciting widespread violence. Martial law failed to contain the outbreak and humans were brought to the brink of extinction. In response, the United States military refashioned into a totalitarian government known as FEDRA which maintained violent efforts to censor information to control the population. Initially, heavily populated areas were bombed and quarantine zones (QZ's) were established to ensure protection from infection.Twenty Years LaterEvacuation leaflet"Seattle Day 1" Subsequently, in response to the formation of FEDRA and the military's oppression, a militia group called the Fireflies was created. The group focuses on waging war against the de-facto government, though most of their efforts are futile given their inferior numbers and resources. Still, they believe they can end oppression through the creation of a vaccine and is one of the last groups to be actively studying the infected and searching for a cure."The Quarantine Zone"
== Biology ==
=== Infection ===
For people who have been exposed to the mutated strain of Ophiocordyceps Unilateralis, the fungus attacks the brain and hijacks the host's motor functions, altering their behavior. The host then goes through different developmental stages depending on how long they've been infected: runner, stalker, clicker, and bloater or shambler; each stage more dangerous than the last. Ellie is the only known human who has an apparent immunity to the fungus, despite being infected for over five years."The Farm" There is also the unique rat king stage."Seattle Day 2"
The infection spreads through direct contact with an infected, via a bite, or indirectly via airborne fungal spores released by a corpse. These spores can quickly infect an individual, making breathing difficult and movement sluggish within only minutes of exposure in spore-dense areas."Seattle Day 2" Only Ellie has exhibited the ability to breathe spores without difficulty."The Outskirts"The Last of Us: Left Behind 
Upon being bitten, the infection will spread through the new host's body, gradually turning them into a runner over a period of two days.I'm not infected The bitten area will turn red and black, causing the host to sweat profusely and become disoriented.Bank robber letter Their eyes may sting and a decrease in motor function makes it difficult for them to write, while irritability and aggression increase.Patient's note Immune hosts, like Ellie, are unable to pass on the infection even when biting other individuals."Seattle Day 3"
Spore development is the last stage in the life cycle of the infected. Once the host has expired, the lifeless carcass serves as a breeding ground for the fungus to spread into the environment. When near death, an Infected will find dark, moist corners to die in. While this may be the end for the host, the fungus continues to grow and spores erupt into the air, infecting anything that comes near. These areas tend to be underground or within dank, abandoned buildings. Living in the QZ's provides safety for the populace since there is significant airflow and restriction to underground facilities."The University"
In order for the fungus to infect and control a host's body, the host must be alive. According to the Center for Disease Control, the victim can only become infected by inhaling the spores directly or coming into contact with bodily fluids from an Infected, usually from a bite.Medical pamphlet Infected individuals must be exposed to specific environmental conditions in order to progress to the next stage of infection; otherwise, they may stay at one stage for an extended period of time. This is presented in the large number of runners within Lincoln and Jackson."Bill's Town""Jackson"
Because their bodies have become so enveloped in fungal growth, Infected are vulnerable to fire. However, the unique rat king stage is so immense in fungal growth that it can survive extensive exposure to fire, able to charge through flames with only minor stagnation.
=== Physical appearance ===
Humans infected with the Cordyceps fungus undergo various unsightly mutations which increase in severity the longer the host has been infected. Runners appear to experience hair loss, discolored skin accompanied with lesions, and bloodshot eyes. Stalkers can be seen with significant fungal growth around their eyes and shoulders. Skin will begin to peel from the face, sometimes causing the nose to fall off, as the fungus begins to break open the skull. Clickers are horrifically disfigured by the infection. By this stage, the skull has been split open due to advanced fungal growth on the brain, growing over or outright destroying the host's eyes, leaving only a maw of teeth which are rotten and jagged. Their skin is covered in mold and scaly fungal growths. The fungal growth on bloaters is so advanced that it begins to form armored plates on the host, while also causing the body to bloat significantly. Clusters of pods filled with mycotoxin will begin to sprout from the body, which can be ripped off and thrown by the host."Bus Depot" The fungus also seems to offer the host some protection against the elements, such as the cold."Lakeside Resort" When the host is killed or dies from advanced fungal growth, the fungus continues to grow throughout the body, eventually emitting spores.
=== Behavior ===
Following infection, victims gradually lose any ability to think freely and begin to behave irrationally as the fungus spreads in the brain and hijacks their motor functions. Relying on primitive, animalistic instincts caused by the infection, they will attempt to attack and/or eat any human they find. This becomes most prominent at the clicker and bloater stages. Clickers can often be seen erratically twitching and sometimes clawing at the fungal growth covering their face, strongly suggesting that there is some vestigial elements of the host attempting to resist the fungus even in later stages of infection. By the time an Infected has evolved into the clicker stage, they develop a primitive form of echolocation due to their blindness and produce loud clicking and croaking sounds, which survivors can clearly hear. Survivors can also evade detection by these Infected as long as they remain silent. According to Jerry Anderson, fungal-growth in the limbic regions normally accompanies the prodrome of aggression in infected patients.
The infected, while having a higher pain tolerance than ordinary humans, are still susceptible to injuries and can be killed through conventional means. A runner, when not attacking survivors, will moan in pain due to the fungal growth deforming its body and clickers will struggle while being shivved. Sometimes infected that still have their entire face intact look remorseful or distressed as they attack, indicating that the infected are aware of what they are doing, but cannot control themselves. Gunshots are capable of startling runners and stalkers, indicating that feelings like fear are still prominent in the early stages of infection. All stages of infected will flail and scream wildly when set on fire or severely wounded. The body of an infected will spasm violently when the host is killed. The infected have also developed sensitive hearing, as they can hear sounds that normal survivors cannot, such as the player hurdling nearby obstacles.
Sometimes, an infected may enter a state of extreme torpor, especially if trapped inside of a building, often attaching themselves to walls and laying dormant. While dormant, the fungus will rapidly sprout from the host, which will eventually calcify and kill them. If stimulated, the infected can break out of this dormant state and roam again. This behavior is seen particularly in stalkers. Runners exhibit similar behavior, laying dormant beneath snow until alerted by prey.
== Stages of infection ==
Name 	Description
Runner 	Runners are people who recently turned into infected. They are defined by their intense speed, sluggish attacks, and tendency to attack people in hordes.
Stalker 	Stalkers are people who have been infected from somewhere between two weeks to a year. Per their name, they stalk and hide from prey in the dark and attack at opportune moments. Some also latch onto walls and allow the Cordyceps to fester, keeping the host alive until prey walks by, at which point the stalker breaks free and attacks.
Clicker 	Clickers are people who have been infected for at least one year. The long time elapse has allowed the fungus to spread all over their bodies, blinding them and forcing them to use echolocation to find prey. However, the fungus has granted them enhanced strength, making them fearsome foes in close-quarters combat.
Bloater 	Bloaters have been infected for several years. The fungus has led them to become slow and blind, yet incredibly strong and resilient with the fungal growth serving as armor plating. Bloaters can also tear fungus from their bodies to use as spore bombs and throw them at their enemies. However, this additional fungal growth makes them vulnerable to fire.
Shambler	Shamblers are people who have been infected for several years and typically inhabit areas thriving with water. While not as physically enhanced as clickers or bloaters, shamblers are able to grapple prey and expel large spore clouds from their bodies, which cause acidic burns on the skin of prey. When killed, the spores explode, releasing a final burst of Cordyceps into the air.
Rat king	The rat king is a unique stage of infected that developed in the Seattle hospital after over twenty years of infection. Formed from several infected combining into one, the rat king is colossal in strength and size, and able to take extensive damage from fire, bombs, and guns. Even after taking much damage, it does not die, but instead, its various infected parts will start to break off from the larger mass and attack along with it.
== Death and corpse ==
Even after an infected individual has died, the fungus will continue to grow; consuming the body's mass to form a fruiting body and releasing spores that infect any human that breathes them. Survivors use gas masks to prevent this.
The process of forming the fruiting body causes the corpse to become skeletal and brittle, fusing the remains to surfaces as it continues to grow. As sufficient time passes, the fruiting body becomes a "moss" that can fill entire structures with deadly fungal growths the color of pasty human flesh. Both of the spores and the fruiting body die quickly when exposed to sunlight, limiting the danger they present.
== Behind the scenes ==
* Runners do not moan as much nor in the same way as in previous beta demos as if in horrific pain but remain silent for the most part. However, they will screech when startled. Some of the concept art in The Art of The Last of Us shows runners wielding tools such as shovels, knives, and rakes as weapons.
* Stalkers appear the least amount of times when compared with other types of infected, with the player encountering them a mere three times in the first game; twice in The Last of Us, and once in the Left Behind DLC. They appear more frequently in Part II, in the form of mini-boss battles.TLOU Part II Demo, YouTube, (Accessed November, 2020)
* In-game clickers jog when chasing Joel or an AI. However, in the cinematics I need a car and Name's David, clickers do sprint. Clickers also sprinted in the PGW trailer for The Last of Us Part II as well.
* Clickers have made cameos in numerous video games since 2013. In Dontnod Entertainment's video game Life Is Strange 2, the protagonist Sean Diaz jokingly makes clicker noises to try to scare his brother Daniel, after pointing out that a mushroom tree looks like a clicker. In Hypixel, one of the most popular Minecraft multiplayer server, there is a game mode known as "Infection" where an infected player has a pixelated skin almost resembling the clicker. In Techland's video game Dying Light, there is an Easter egg in which a zombie with its head shaped like a clicker comes out of an elevator. In addition, it will drop an item called "Clicker" when killed. In the cartoon The Amazing World of Gumball, the episode "The Parasite" features a clicker when Gumball merges with Darwin in order to warn Anais. He also mentions that he takes the zombie's form from a video game. A clicker appears near the end of PlayStation's Greatness Awaits trailer.
* Clickers do not click the same way as in previous beta demos where it would sound more like constant tapping of the tongue. In the final game clickers click by waves of croaking rather than constant tapping.
* In The Last of Us, if the bloaters in the Pittsburgh hotel basement and UEC dormitory kill Joel, they will actually knock the mask off of his face in a special death animation."Pittsburgh" When controlling Ellie, the bloater death scene changes; the bloater simply punches Ellie, killing her with its sheer strength.
* Bloaters are the only stage of infected from The Last of Us that do not appear in the Left Behind DLC.The Last of Us: Left Behind
* In an interview with Neil Druckmann discussing The Last of Us Part II, he hinted that the environment itself plays a role in the various states of the infected's lives. When discussing the shambler, it was stated that the team didn't throw in a new enemy type just for the sake of it, they carefully thought out how it fits into the lore of the world of The Last of Us; Druckmann is quoted as saying "In the first game, there is all this documentation about the different stages [of the infection], now we have to justify why there are different stages. Why are there mutations of these things? Without getting into it here, there is something about the environment and how much time has passed that has allowed these mutations to occur."Druckmann interviewed for PlayStation 2019 blog, PlayStation Blog, (Accessed January, 2020)
* According to co-directors Anthony Newman and Kurt Margenau, the rat king's appearance took inspiration from the films Zygote and Annihilation, as well as the video game Inside. Additionally, its battle took inspiration from the boss fights of Magni and Modi from God of War and Elieen the Crow from Bloodborne. A note hinting that there were more rat kings elsewhere, as well as a line from Abby that explicitly names the creature ("Fuck this... Rat... King?!") were cut from the game."The making of a Rat King: How Naughty Dog created its scariest foe in The Last of Us Part 2", GameRadar, (Accessed August, 2020)
* As the rat king, the stunt performers were tied to each other while performing mocap with Kelli Barksdale stacked on top of Jesse La Flair and Walter Gray IV.Becky Dodd (@thebeckydodd), Twitter, (Accessed December, 2020) But for the separation, Chris Robbins and Amy Johnston each played the bloater and stalker half respectively.Jeremy Yates @Jeremy_Yates, Twitter, (Accessed January, 2021)
* The rat king is based on a real life phenomenon, where numerous rats are found constrained together because their tails intertwine or are bound together. Like the sole "rat king" infected seen in the game, real-life rat kings are rarely seen.Rat king - Wikipedia
== Gallery ==
=== Concept art ===
Runner.png|Runner face concept art.
Stalker.jpg|Stalker concept art for the face.
The-Last-of-Us-Infected.jpg|Concept design for a clicker
Bloater.jpg|Bloater concept art.
LAUP2-Shambler-731x519.jpg|Shambler concept art.
=== The Last of Us ===
Military Pamphlet.png|A military pamphlet that outlines the stages of infection.
The Infected.png|Several common varieties of infected.
Joel about to get eaten by an infected.jpg|A clicker trying to bite Joel.
the infected's face.jpg|A close-up of a clicker
TheLastOfUsScreen3.jpg|Joel killing a "clicker" in the VGA announcement trailer.
The Last of Us Screenshot #13.jpg|Joel encountering a stalker in the hotel basement.
Joel strangling a clicker.jpg|Joel shivving a clicker.
American History X.jpg
Joel Punch.jpg|Joel fights a runner.
Punching a runner.jpg|Joel punching a stalker.
Too many clickers.jpg|Joel, against a trio of clickers
Ellie Clicker.jpg|A clicker attacks Ellie as Joel tries to shoot it.
Runner hits Joel.jpg|A runner attacks Joel.
Tommy brick.jpg|Tommy hitting an infected with a brick.
Joel chokes Runner.jpg|Joel strangles a runner.
Bloater closeup.jpg|A bloater in Salt Lake City.
Bloater charges at Joel.jpg|A bloater charges at Joel.
Bloater attack.jpg|A bloater throws a mycotoxin.
Bloater kills Joel.jpg|A bloater kills Joel.
Ellie Bloater.jpg|Ellie prepares to combat a bloater.
Choke Stalker.jpg|Joel choking a stalker in the sewers.
Clickers vs Humans.jpg|A clicker attacks a cannibal, quickly killed by oncoming humans.
Human vs Infected.jpg|The cannibals fight two clickers.
Clickers Humans.jpg|Cannibals fighting a group of infected.
Ellies bite (spring).jpg|Ellie's bite mark, noticeably redder and throbbing.
Stab Runner.jpg|Ellie saves Joel from a runner's bite.
Clicker tackles Joel.jpg|A clicker attempts to bite Joel.
Melee Clicker.jpg|Joel striking a clicker with a pipe.
Spore subway.jpg|A developed spore cadaver, in the subway.
=== Part II ===
Red1.jpg|The shambler.
Rat King close up.jpg|Close up of rat king.
Rat King finds Abby.jpg|Abby being spotted by a rat king.
Dying Rat King.jpg|Rat king that has just been defeated.
== References ==
es:Infectados
pt-br:Infectado
de:Die Infizierten
fr:Les Infectés
it:Infetti
pl:Zarażeni
ru:Заражённые
Category:The Last of Us: American Dreams groups
Category:The Last of Us Part I groups
Category:The Last of Us Part I enemies
Category:The Last of Us: Left Behind groups
Category:The Last of Us: Left Behind enemies
Category:The Last of Us Part II groups
Category:The Last of Us Part II enemies