Mojo is a companion pet found in Zul'Aman by using hex sticks on frogs there to get rewards. Mojo is one of those rewards, with a 2% estimated drop rate.
In a recent patch, Zul'Aman was changed so that 5 people are no longer required to open the door. Just talk to Harrison Jones after entering and then bang the gong with him and he will open the door for you. When you see the door open, be aware that 2 elites and 3 non-elites are about to attack you, so you can either run out or fight them. I posted this guide on wowhead a while ago, but I decided to update it slightly and post it here, with the new change that you can do this without 4 other people now.
The best method for farming Mojo that I found was running the eagle gauntlet and resetting it repeatedly. This will take a decent soloing class (plate or a pet helps). You will be farming Mojo by concentrating on killing the groups of two trolls. Groups larger than two are possible, but harder, and none are found in the eagle gauntlet anyway.
To start the gauntlet, run down the leftmost steps from the entrance and turn left. You will see an Amani'shi Lookout standing there. He will not aggro, instead, he will run up the hill to start the event. This starts about a 30 second timer until the first eagles and troll warriors spawn. During this time, you want to run up the hill and kill the first two mobs. Focus fire the one without the shield first, as he casts chain heal occasionally, which can be interrupted. He can also be stunned, though I don't think Repentance works, so probably not other CC also. When you finish those two, loot them quickly (35% drop of the stick per mob, according to wowhead) and continue up the hill after healing up if you need to. Move fast, though. Keep continuing to kill the groups of two until you get to the steps. Halfway up the steps is a unique troll that is controlling the event. Stop here.
During the gauntlet, patrols of eagles will come down from the steps behind the troll on the steps at somewhat random intervals between 15-45 seconds. The eagles don't have much health and can be aoe killed fairly easily, or just killed when you finish the other mobs. They do not hit hard. Also, there will be two Amani'shi Warriors spawning at the beginning of the gauntlet where the lookout was and running up. Whenever they get to the top of the first hill, they will aggro no matter where you are in the instance and run to you, pulling any mobs on the way. The eagles can be avoided if you step out of their patrol route and don't aggro them, but the warriors must be killed. They only have about 10k health a piece, though, so they go down fast. However, they have a charge ability so if you're struggling with surviving while fighting the stationary groups of trolls, then wait for the next patrolling warriors to come and kill them before engaging the next stationary group. You will almost always get a group of eagles while fighting, though.
When you get to the controlling mob on the steps, kill any eagles or warriors you have up, then mount up and run back down the way you came. You can jump up on the divider wall going down to make it down faster. Keep going down and turn left to find the forest frogs. Use any hex sticks you have found on the frogs there, one stick per frog. If you are lucky, Mojo will spawn and run over and jump in your pocket. Otherwise, the frog will turn into an ally who will either be a vendor who runs back to the entrance and stays there or a random ally who will drop a treasure box for you to loot. These contain random boe greens and Amani charms which have an effect while in the instance. Use these if you want.
When done looting (the warriors will still be spawning, so kill any that come at you as you can't loot the boxes in combat), mount up and run toward the entrance. If you stand in the doorway going into the ally area and wait, you should usually drop combat and the gauntlet will reset. If they follow you, then just run out and run back in. You can also get naked and die and reset the gauntlet. Then, just rinse and repeat from there. It only took me a few hours to get my Mojo, and most was learning the gauntlet, as I had never been to ZA before.
Good luck!
TL;DR:
- Go in, turn left.
- Kill groups of two, start with caster.
- Watch for eagle and warrior patrols.
- Try to kill warriors before aggroing next group.
- Stop at mob on steps, run away and use hex sticks.
- Run to the entrance to reset the gauntlet.
- Repeat.