There are several zombie types in Back 4 Blood that players will have to face throughout the campaign.
There are of course hordes of common infected Ridden that swarm to loud noises, but many of the zombies in Back 4 Blood have unique abilities to defeat the Cleaners. Players even have an opportunity to play as some of these special Ridden types in Back 4 Blood's player-vs-player mode, which pits a team of Ridden against a team of Cleaners.
Back 4 Blood Zombie Types
Stinger-type Ridden all have greater mobility compared to other Ridden, but generally have less health. Most of these types of Ridden also have a projectile that enables them to poke at Cleaners from a distance without risking taking damage.
Hockers can launch a sticky projectile that pins players in place and deals damage over time. The Stalker is a melee-styled special Ridden that uses its agility to pounce on players and drag them away from the team. Stingers have a projectile that blurs the players vision.
Reeker-type Ridden all have bloated bodies that explode upon death similar to the Boomers of Left 4 Dead.
The Retch is capable of vomiting on Cleaners from a disturbing distance. The Exploder is able to detonate at will if he gets close enough to a player, causing massive damage. Reekers can also charge players and knock them back.
Tallboy-type Ridden all have a massive right arm that is more than capable of crushing players. Shooting their inflamed shoulder will blow the arm off the Tallboy and make them much easier to deal with.
There are Bruisers which can pound the ground in a frenzy and smash Cleaners. Crushers can use their massive arm to squeeze players and incapacitate them. Basic Tallboys can also charge at players in short bursts of speed.
Snitchers aren't worth much in combat, but if they aren't killed quickly after their alerted then they will scream and cause a horde of Ridden to chase the player. Snitchers have a long swollen neck that makes for easy kills.
Hags are a bit more rare than other special infected, but they are among the most dangerous of them all. They wonder around slowly initially, but if they're damaged or startled they will chase a player and attempt to eat them whole.
Ogres are massive special Ridden that are a combination of many dead bodies. They are slower than most other Ridden, but deal huge amounts of damage and take take a beating before dying.
Breakers are to Back 4 Blood what tanks are to Left 4 Dead. They are large, powerful and agile enough to jump large distances and charge players.