Zul'Gurub (ZG) enchants are very sought after by raiders as they can add extra stats to a head or leg item. Each enchant is class specific and can only be found inside ZG. The ZG enchants were introduced in patch 1.7, and the required items were changed in patch 1.11. The required items described below are from patch 1.11.

The ZG enchants requires you to be friendly with Zandalar Tribe in order to deliver the quests. The enchant can only added to a head or leg item. To get the enchant you need two items Primal Hakkari Idol and a class specific Punctured Voodoo Doll. Primal Hakkari Idol are dropped by Jin'do the Hexxer and Bloodlord Mandokir. The Idol is bind on pickup and can not be traded. Punctured Voodoo Doll is found inside a Jinxed Hoodoo Pile. The location of each pile can be seen in the image below. It is possible to trade dolls with other players as it is not bind on pickup, but the doll is unique so you can only have one at a time.

Jinxed Hoodoo Pile location image is taken from the Twinstar

Each ZG enchant's required items and stats for each class can be seen in the table below.

CLASSREQUIRED ITEMSSTATS
DruidPunctured Voodoo Doll and Primal Hakkari Idol +10 stamina, +10 intellect, +24 healing
HunterPunctured Voodoo Doll and Primal Hakkari Idol +24 ranged attack power, 10 stamina, +1% chance to hit
MagePunctured Voodoo Doll and Primal Hakkari Idol +18 healing and spell damage, +1% to hit with spells
PaladinPunctured Voodoo Doll and Primal Hakkari Idol +10 stamina, +7 defense, +24 healing
PriestPunctured Voodoo Doll and Primal Hakkari Idol +10 stamina, +4 mana per 5 sec, +24 healing
RoguePunctured Voodoo Doll and Primal Hakkari Idol +28 attack power, +1% dodge
ShamanPunctured Voodoo Doll and Primal Hakkari Idol +15 intellect, +13 healing and spell damage
WarlockPunctured Voodoo Doll and Primal Hakkari Idol +10 stamina, +18 healing and spell damage
WarriorPunctured Voodoo Doll and Primal Hakkari Idol +10 stamina, +7 defense, +15 shield block value