Scale of Onyxia
Scale of Onyxia is a rare scale that can only be obtained by skinning the Black Dragonflight Broodmother, Onyxia. the skinner needs to be at least level 315 in order to skin Onyxia and it will produce 1-4 scales. Onyxia can be found in a small cave in Dustwallow Marh called Onyxia’s Lair, a 10-25 raid party is required to enter.
See below for the exact location to find Onyxia in WoW.