Black morass have Blackwater Crocolisks, Blackfang Tarantula, and Sable Jaguars which you could farm for Knothide Leather/Scraps and Netherweb Spider Silks. As a bonus, and since its an instance the mobs don't reset as you pull them--they will chase you indefinitely. So if you are a great AoE class, you could easily train a number of beast easily. Be warned though, since these mobs have at least 10k hp and does 100-400dps. Single pulling/DPS could also be done easily.
Tips:
1) Mount and train mobs while strafing left and right. This will round up mobs better.
2) Decent geared prot pallies (aka tankadins) are perfect for soloing. I have not personally tried it, but ive seen the potential. Consecration and retribution aura is insane AoE DPS. How a paladin choosed skinning is beyond me.
3) If you are a Mage, a warrior or a Warlock, grabbing a healer to assist you isn't a bad idea.
4) You will get a lot of vendor trash! And conveniently, the vendors are a few seconds outside the instance! The crocs have a 60% chance to drop a tooth which vendors for 11s and stacks up to 20.
5) If you don't use your netherweb spider silks you can sell them in the auction house. In my server they sell for 6-10g each.
6) These mobs also drop a lot of greens. In my experience, at least 2 greens every 15 kills.
7) You don't get keepers of time rep.
You cannot use the dragon conjuring item (Chrono-beacon) given by the NPC by the entrance to kill the mentioned types 3 mobs.
9) Don't wait for the mobs to respawn, simply reset the instance.
10) Don't get near Medivh (or talk) since it will start the event
11) Watch out for the stealthed Sable Jaguars (They have stealth detect too btw). Wait for these guys when youre doing an AoE round up since they are slow when they chase yo when stealthed.
I don't have a gold/hour numbers yet, since i'm pretty slow at killing these mobs in the mean time. But in my estimation, if done efficiently, this could yield 400-700g/hour selling everything including the greens.
Note: Its too late but a similar guide existed in this forums. But i wont delete this since it has a different strategy and content.