This only works if you are grinding for scryers rep at Mana Forge Coruu.
You must proceed through the quest chain starting at Thottbot World of Warcraft: Quest: Report to Spymaster Thalodien
and stop at Thottbot World of Warcraft: Quest: Information Gathering.
At this point you will recieve Sunfury Disguise.
The beauty of this disguise is that it is instant, and works in combat.
Say you agro several sunfury mobs and get ganked, (or just plain pulled too many). Pop the disguise and you will be instantly friendly with mobs. They will reset and then agro the ganker if he is close enough to them.