If you don’t already know this, there are two different versions of the mantis shrimp appendage. I’m a big fan of the smasher myself, but some people prefer to stab their food. A Smarter Every Day “InfoGIF”.
Here’s the SED video on smashers: https://www.youtube.com/watch?v=LXrxCT0NpHo
If you’re in the mood for some hardcore science, here’s an article you might enjoy: