Picture via Wohead.
Ever wanna look like a Mogu?
Well with the Chalice of Secrets you can!
When you use the chalice when it is active the next killing blow you make against a player will transform you into a Mogu for 5 seconds. While you are in mogu form no actions can be taken against you. The chalice has a 10 minute cooldown.
The Chalice of Secrets drops from Urgolax a rare spawn in the Vale of Eternal Blossoms.
I just love transformation items in WOW.