Hyperion Greaves

Source
This item drops from:
 * Trash mobs in Molten Core
 * Nefarian in Blackwing Lair
 * Gahz'ranka in Zul'Gurub
 * Lord Kazzak in Blasted Lands
 * Onyxia in Onyxia's Lair
 * Highlord Kruul in Silithus