Hunters are the armed civilians who took Pittsburgh from FEDRA and now ambush anyone passing through to strip them of supplies. You fight them through the Pittsburgh and The Suburbs chapters.
After a protest was crushed, Fireflies helped the citizens of the Pittsburgh quarantine zone rise up. The fighting lasted fourteen months before FEDRA's captain pulled out. The rebels then killed the Firefly agitators too and turned to preying on travelers. Their leader is talked about but never seen.
Hunters are roughly as tough as Joel in close combat, but they lack military training and squabble among themselves, which you can overhear. Use stealth to cut down their numbers, since a big group will overwhelm you. A smoke bomb thrown near the Humvee makes the gunner hesitate long enough for you to reach cover.
Stalker
Stalkers are stage two infected that hide, circle you and strike from cover. They keep a runner's sight and speed but fight harder, and in Part I they are rare: two main encounters for Joel and one in Left Behind for Ellie.
Infected
The Infected are people taken over by a mutant Cordyceps fungus, and they are the main threat between every human fight in The Last of Us Part I. In Part I and Left Behind you meet four stages: runners, stalkers, clickers and bloaters, each harder to kill than the last.
Bandits
Bandits are rural raiders who live around Jackson County and attack Tommy's settlement and its hydroelectric dam. You fight them in Tommy's Dam, first at the dam and then at the ranch house.
Runner
Runners are stage one infected, people turned within the last couple of days. They still see, move fast and swarm in packs, so the danger is numbers rather than any single runner.