Yor

Yor is a summoned boss in front of Nexus-Prince Shaffar in the Mana-Tombs in Auchindoun, and is only summonable in Heroic mode. After completing the quest The Mark of the Nexus-King and obtaining either Shaffar's Stasis Chamber Key or The Eye of Haramad, one can open Nexus-Prince Shaffar's Stasis Chamber.

Adventure Guide
''A "gift" from Illidan Stormrage to accompany Nexus-Prince Shaffar, Yor is a void hound of unlimited savagery and power. The prince's advisors warned him that Illidan's demonic gift was most likely a ruse set to betray Shaffar once he had met his goals. The prince fed those advisors to Yor... but has since kept the hound in a stasis chamber, just in case.''

Strategy
Position Yor facing away from the group so they are not hit with the fire breath. Melee DPS attack from the back side and keep others at range. He is a simple tank and spank fight.

Objective of

 * Burning Legion (mission)