The Black Drake Mount is a awesome looking Drake mount that is now very easy to get. To get it you have to kill Sartharion in the Obsidian Sanctum 10 man with the 3 other drakes still alive. It is a 100% drop if you manage to do this. With decent gear this is very easy. In the video below you can see how i do it with my Item Level 502 Rogue, the fight only takes about a minute and the whole instance takes about 5 minutes and i hardly loose any health at all!
So to start you will want to clear all the trash mobs. Leave the dragons alone or else you won’t get the Reins of the Black Drake. When you have cleared the trash, go kill Sartharion and just don’t mind the Drakes. Try to avoid the waves of lava, don’t worry too much though. Once you have killed Sartharion , loot him and you will get the Reins of the Black Drake.
Video of me soloing Sartharion :