I have harvested and eaten a lot of elk and deer in my life. Elk steaks and roasts can be great if done right, and I even like deer. But I have learned that "burger" means ground beef, and ground beef ONLY. I absolutely will not eat ground elk or venison unless I have to gag it down to avoid offending a host who is serving it to me (which happens occasionally living in Montana with friends and family who hunt).
You could try making taco meat out of it, using so much seasoning that you drown out the flavor of the meat as much as possible. But even then ground elk or deer is just not good.