How to get Elder Dragon Jaws

Other than Gaoren’s quest. Is there really no other way to obtain the specified material rather than repetitively hacking, slashing, bonking or piercing its face and sometimes leg for 20 minutes straight, in every single quest, hoping it to drop in the rewards, which is like only on 1 per 10 hunts? I really really wanted to craft the Guan Transmog so bad.