You will need:
Stronglimb Deeproot, ancient of war and chief defender of the Living Grove south of Sylvanaar.
Find him by heading west across the bridge that traverses the Bloodmaul Ravine.
Return his hewn trunk to Tor'chunk Twoclaws inside the Thunderlord Stronghold inn.
Stronglimb Deeproot walks along the north-south path leading south from Sylvanaar. Be careful not to get too close to the Alliance town or the guards will attack.
What's that you have there? You're a strong one!
Stronglimb Deeproot's Trunk! Did you chop him down by yourself?
I bet you did. You know, Rexxar and I are looking for a young, strong <class>, such as yourself, to help out around here, especially with the problems we continually have with the ogres. Make sure that you follow-up with me on that possibility.
Well that trunk's definitely proof, which means you're here to collect the bounty and not to listen to me talk. Go ahead, take your pick.