From WoWWiki

General Information

• Level (Elite): 70
• Location: Trash mob in The Arcatraz
• Type: Humanoid

Attacks and Abilities

• Polymorph (5 sec duration)
• Sonic Boom (Counterspell + about 1000 Arcane damage)
• Arcane Haste (buff)(decreaes time between attacks by 50%)

Try to keep this mob CC'd the duration of the fight and kill it last...you don't want your healers getting sheeped.

These mobs also have a self-buff that increase spell casting speed by 50%. A mage can spellsteal this to greatly increase their DPS.

Immune to Mind Control on Heroic mode.