If you're like me, and you tried getting this quest with a character who hadn't done any Nagrand quests, you'll need to start those. The axe will not drop from talbuk, no matter how many you kill, until you reach a certain point. All you have to do is the Might of the Warsong Quest that's on the map, near the entrance to Nagrand. Follow the process to Wor'var, and you'll get eventually get the Lantresor quests started. Do all of that, and when you get back and finish your Wor'var building, Ogka will have a quest for you. Lo and behold, it's a quest to kill talbuk! As you kill them for their horns, the axe will drop, allowing you to go back to Ogka and get those sweet, sexy pants.
Good hunting! Lok'tar ogar!