This is a United Cutlery Indiana Jones Khyber Bowie Knife. I have two of these left from a collection of parts I bought from a friends family after he passed, Mike Chestnut. Mike was the king at coming up with great toppers for his pins, and would often times buy extras of the things he did and resell them to others wanting to do the same. I purchased one from him myself several years ago, as he and I were redoing my IJ and I made mention of loving the knife on his. Turned out he had one then and had a couple more left when I ended up buying his parts from his dad. These are new in the box and this item is no longer produced. To mount them on a backbox you will need a little L bracket, which you can pick up at any hardware types store. They look great on the game and my game is pictured there with mine. They made a few different IJ knives but this one is the only one produced with the mount that you see here, which makes it the perfect size for the top of a backbox, plus it just presents so well. You may also just be a huge Indy fan and only want it as a collectible, which is totally understandable.
If you have any questions feel free to reach out at firstname.lastname@example.org or 615-598-0024. Thanks for looking!