Onyxia Scale Cloak
While some capes provide more fire resistance, the Onyxia Scale Cloak is essential for most of the bosses in Blackwing Lair since this cloak prevents from engulfing the target (the DoT after Shadow Flame hits).
1-4 Scales of Onyxia drop when Onyxia is skinned. 315 skinning was required to skin her, which necessitated at least two out of three of , , and +5 skinning enchanted gloves before the Burning Crusade expansion was released. Although Onyxia was changed to a level 80 encounter with Patch 3.2.2, she still can be skinned to acquire Scales.