Breakers are hulking male Freakers that soak up huge damage and can knock you flat with one swing. Treat each one as a mini-boss: stay at range, lead with explosives and finish with headshots.
One hit from a Breaker launches you backward, and a grab deals heavy damage. It resists flinching from bullets and most melee hits. It keeps pace with you on foot and climbs after you. Flashbangs and smoke bombs are your best way to break contact.
Fight from a hidden spot. Open with pipe bombs, grenades or mines, then switch to headshots with a shotgun or sniper rifle. When it closes in, blind it or smoke it, move to new cover and repeat. Do not stand and trade blows.
Your first Breaker guards the cargo at the Red Cross plane crash in Playing All Night, deep in Ripper territory. It is busy killing a Swarmer when you arrive. More show up as the game goes on, especially around Crater Lake. Deacon's journal treats them as a fairly new mutation.
With Executioner unlocked, sneak up on an unaware Breaker for a stealth kill. That counts as a knife kill for This is a Knife.
Reachers
Reachers are fast, hairy Freakers that charge, maul you, then back off to set up an ambush. They hit as hard as a Breaker with about half its health, so steady aim matters more than raw firepower.
Image: Bend Studio / PlayStationRippers
The Rippers are a Freaker-worshipping cult that shaves, scars and drugs its members and hunts anyone who will not join. They hit the northern regions hardest, and with no body armor they go down fast if you hold a choke point.
Bleacher
Bleachers are pale, shirtless Swarmers with about 50% more health and a harder hit. They are a newer mutation you meet later, and the same tactics as Swarmers work if you bring a few extra rounds.
Deschutes County Militia
The Deschutes County Militia is Colonel Garret's army in the south and the best-trained human force you meet. For much of the second half you work for them at Diamond Lake and Wizard Island. Their soldiers are also the toughest humans in the game to kill.