User:Mr. Fataled/Harpoon
From Worms Knowledge Base
That worm... That damn worm... If only it was close to you, you could... Oh, wait. You have a Harpoon! It looks and firing like a Ninja Rope, but the launcher is navy blue, and the rope itself has the bigger and more evil-looking hook.
After hitting the ground or any other object, it simply comes back to you, but after hitting a worm, it attracts it to you and dealing some damage. You can free it in the air, if you have fast enough reaction.
There's numerous uses of that weapon. You can drop enemy worm into the water, minefield. Or group multiple worms into a pile to damage them all. Or trapping it on some hole and then leaving it using some transport.
Programming would require some new code for attracting worm, but I don't think it's too hard to implement.