I designed a harpoon for G1 Longtooth based on the Marvel Comics appearance. Someone bought one and used it for their custom figure. Really like it. Again, NOT my figure, but I helped a tiny bit with the weapon. Longtooth Harpoons by mathewignash on Shapeways
Oooh, very nice custom. Looks great and cool idea!!! (Yes, I read that it's not yours) Reminds me very much of IDW Longtooth: