Isn't it a smasher? Yeah, a smasher.

The whole world's waiting for you. You're a smasher!

Now, the other type of mantis shrimp is the smasher stomatopod, and these guys open up snails for a living.

So, the smasher raptorial appendage can stab with a point at the end, or it can smash with the heel.

So, this what I saw, on every single mantis shrimp limb, whether it's a spearer or a smasher, is a beautiful saddle shaped structure right on the top surface of the limb. And you can see it right here.