Crown of the Wayward Vanquisher

Crown of the Wayward Vanquisher is a tier 8 armor token. It can be exchanged in Dalaran for the following items:
 * Conqueror's Terrorblade Helmet
 * Conqueror's Darkruned Faceguard
 * Conqueror's Darkruned Helmet
 * Conqueror's Kirin Tor Hood
 * Conqueror's Nightsong Cover
 * Conqueror's Nightsong Headguard
 * Conqueror's Nightsong Headpiece

Source
This item can be found inside the Cache of Storms after defeating Thorim in the 25-man version of Ulduar.

This item is also sold by the following vendors for :
 * in Dalaran
 * in Dalaran