The Last of Us’ monsters are not your average zombies. Yes, they’re gross. Yes, they bite. But they’re not reanimated after dying. Instead, they’re living people who have been taken over by a fungus called Cordyceps — their whole thing is multiplying and spreading the infection as far and wide as possible.
The Cordyceps infection evolves over the course of an infected person’s lifespan, which makes the Last of Us games’ infected that much scarier. Each of these different evolutions creates a unique threat. For instance, the first stage — when a person has first turned — is super fast and can detect uninfected people to chase. Clickers, a later stage, are blind, with mushroom-like growths splitting open their faces and obscuring their vision.
We haven’t seen all of the infected types from the games represented yet in HBO’s The Last of Us, but they’re probably coming.
The first stage of infection happens as the fungus spreads through the body. In HBO’s The Last of Us, the show’s creators slipped in an infographic to explain how long it takes for the infection to spread inside a person, depending on the bite location: On the head or neck, it’s quick, within minutes. If the bite’s on an extremity, like a leg or arm, it’ll take closer to 24 hours. The first signs of infection include coughing, slurred speech, muscle spasms, and mood changes. (Remember the old lady in episode 1? The muscle spasms were the first sign.)
Runners are fast — inhumanly fast — and often travel in big groups. These look a lot like regular zombies, because they haven’t started sprouting mushrooms yet.
Stalkers are probably the most common type of infected. They’re slightly more advanced than Runners and have visible changes — fungus grows out of their bodies, and sometimes their flesh is visibly decaying. Stalkers are not as fast as Runners, but they’re very deadly, always lurking, and ready to attack. In the games, Stalkers sometimes grow onto walls with mushroom tendrils holding them in place. When you walk by, they’ll break free in a surprise attack.
We’ve seen these in HBO’s The Last of Us, but completely grown into the wall and seemingly dead. In some cases, it seems like the fungus network may still be alive, but in others, it’s clearly dead and crumbling.
Probably the creepiest sound in the show (and the games), Clickers are infected that have been around for a while, with mushrooms visibly protruding from the head, taking over the eyes. They can’t see, so it’s necessary to move slowly and quietly near them. Any noise will alert a Clicker, and they’re very good at finding their prey using audio cues. They’re easy to identify because of their signature clicking noise, a form of echolocation, and because of the massive fruiting mushroom sprouting from the head. We saw a couple of these on HBO’s The Last of Us in Boston’s historical museum in the second episode.
Bloaters are the most advanced stage, and there are a few different variants within the group. We haven’t seen one of these on the show just yet, but HBO previously teased a Bloater in one of The Last of Us’ trailers. You can tell an infected is a Bloater because of the size — they’re big, grotesque, and, naturally, bloated with decaying mushroom bubbles. Bloaters and Shamblers are slower but really strong, and they can have a surge of energy to lunge toward an enemy. The layers of fungus act like armor, making them difficult to kill, too. They can also rip those growths off their bodies and throw them, sending damaging acid everywhere. If you get caught by a Bloater in the game, it’s an instant kill — and it rips your head in half through the jaw.
Shamblers are basically waterlogged Bloaters found more on the West Coast in the games. They’re pretty similar, but they emit an acid gas that they spit at enemies.
We’ve only seen one Rat King infected in the Last of Us games, and it’s pretty gnarly: It’s a shambling mass of multiple infected Clickers, Runners, and Stalkers all mashed together. It may be an anomaly, and who knows if we’ll see one in the first season of The Last of Us. The battle against the Rat King in The Last of Us Part 2 takes place in two stages, and the monster breaks apart into different infected. It’s got all the characteristics of the infected that comprise it, throwing mushroom bombs and emitting poison gas.