Solution: GIJoe 1990s grappling hook
Anyone need a replacement missile? I think the shooter was neon orange, don't remember which GIJoe it came with. Model is in two pieces (as was the toy): the stem and the hook. the 4-prong model is the original, the 3-prong is the one I always thought it Should have; the Unihook is just there for if you want to make a 5 prong or whatever.