Crown of the Forlorn Vanquisher

Crown of the Forlorn Vanquisher is a tier 11 armor token. It can be exchanged at in Stormwind City or  in Orgrimmar for the following items:
 * Firelord's Hood (heroic)
 * Magma Plated Faceguard (heroic)
 * Magma Plated Helmet (heroic)
 * Stormrider's Cover (heroic)
 * Stormrider's Headpiece (heroic)
 * Stormrider's Helm (heroic)
 * Wind Dancer's Helmet (heroic)

Source
This item drops from Nefarian in Blackwing Descent on Heroic mode.

It can also be purchased from the following vendors for :
 * in Stormwind City
 * in Orgrimmar