Bosses are powerful zombies that can be founded in buildings with a purple skull icon.
Sgt. Drebin is a boss found in the police station in episode 3. He is fought in the quest where you must get a DEAD vial from the station. Although he is thought to be a zombie police seargeant, he is most likely a military one who either wandered into the police station or was helping out the police prior to being infected because of his green military-style uniform and beret (The standard police uniform is black). He has over 4000 health and is hard to kill but he is worth the fight because he drops many useful items including an AK-47.
Raging zombies are powerful zombies like bloated zombies, it can wear random costumes (Police, commander, chef...)
Paulie is a boss that has more than 300 health, he can be located in a building next to the raider in Ep. 2. Upon death, he drops severed arms, an excellent weapon for begineers.
Chopper Dave is your first boss, he is in Ep. 1 after you are about to go to next Episode and getting a call like "Give me your...brrr...aughhh..." this is the first victim to be infected in the game.
Test subjects are zombies similar to bloated zombies, it only spawns for a mission from Dr. Dexter's friend. These zombies have a special costume that suits perfectly for test subjects
Zombified raiders are zombies similar to Test subjects which is smaller and looks like regular zombies, spawns only for mission from Raider. These are infected people from the gang called "The Raiderz"