Thingar can be found by leaving the encampment via the southwestern exit. Follow the mountain ridge to your north as it wraps around and steers your in a northeastern direction. Be careful as you travel this way because there are elite giants who will very much hinder your progression if you get to close to them. At the end of the path you fill find Thingar. He does not hit very hard but he does have a rather large health pool so be prepared for a potentially difficult fight. Once you down Thingar return to Quarrystone Basin and speak with Passel Drobe for your reward.