Hakkari Witch Doctors are found inside the lvl 60+ raid-instance of Zul'Gurub.
Hakkari Witch Doctors have an ability to polymorph a target into a frog (Hex). Hexxed targets can still be attacked and will not break the Hex. If a Witch Doctor is part of a group with a Gurubashi Blood Drinker, the Witch Doctor can be mind controlled and Hex the Blood Drinker, neutralizing the AoE life drain and making the Blood Drinker easy to kill.
Patches and hotfixes
Patch 1.7.0 (13-Sep-2005): Added