Types of Undead
Traditional undead are typical zombies, but actually quite fast corpses and will make up the bulk of the undead hordes. These zombies seem to be the only kind to be able to grapple John (or the kind that do it the most), possibly because they hold no other special characteristics unlike the other types of undead. They are found mostly in massive hordes. Though if they grab you off guard they can seriously injure or even kill the player.
Bolters move about much more quickly by scampering on all fours making them hard to target. Their main attack is biting and clawing at the player in a rapid succession, making them extremely dangerous when in hordes. Bolters appear to be small, and frail looking, and they walk like they have a limp until they see you, ironically making them the slowest Zombie as well if they are on just their legs. They are usually easy to spot from a distance. They emit high pitched screeches.
Bruisers are big, fat, and slow, with stamina above other zombie types making them tough to kill. They will also charge at the player from a distance to knock him down. They can be seen pretty easily when within a group of zombies. It is recommended to try and take them out first since they can knock down Marston quickly making him a meal for any nearby Bolters.
Retchers glow green, smell worse than other undead, spit toxic bile at the player, and explode when killed, causing damage to the player (killing the player if playing as undead John Marston) as well as any other Undead or NPCs caught in the blast. They can be found in and around Gaptooth Ridge and most of Nuevo Paraiso.