Onyxia Scale Cloak is crafted by Leatherworkers with a skill level of 300.
The components are:
The pattern is automatically learned when you turn in the if you are a Leatherworker.
For Horde Leatherworkers you must now talk to Overlord Runthak to learn the pattern.
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.
Patches and hotfixes
Patch 1.6.0 (12-Jul-2005): Added