I have a ninja grappling hook that I got in Chinatown. The barbs at the end look like dragons. It is more of a show piece than something you would actually use but I tried it once and it works.
I also have several swords and throwing starts and I display them all on the wall in my man cave. I have always been fascinated with ninja culture and I watch a lot of Kung Fu movies so it just makes sense to put the stuff up on the wall.