So, as I was envisioning different Rahi for G3 at school today, I just randomly came up with the idea for a CCBS version of the Tarakava (or in this case, due to the coloration) Sand Tarakava arm.
The orange torso is mostly a place-holder, assuming I ever finish making the CCBS Sand Tarakava.
In this case, I was mainly looking to adapt the concept of a boxing glove/praying mantis/lizard hand together, which I honestly had a hard time envisioning. Eventually, as I visualized some concept art for a Sand Tarakava reaching out from below the sand to grab an unsuspecting matoran, the shape of the arm and structure just came to me and I figured out how to adapt it to CCBS.
Here’s another angle of the Sand Tarakava arm. The idea is that the Tarakava’s hand, instead of being a clenched fist, is instead more of a curled-up grasp, sort of like the real-life Praying Mantis martial arts style.
On the back of a hand is a bony plate and armor to not only protect its hand from the impact but to also provide additional force to each punch as well.
Fully outstretched and slamming into prey with a sudden snap of a lever, the Sand Tarakava can deal devastating, unforeseeable strikes from beneath the sand where it dwells.
As demonstration, we have a disembodied Sand Tarakava arm punching Iron Doom in the face. 
“Bionicle was the ORIGINAL story-driven Lego theme!”
(No offense towards Ninjago though, I am a die-hard fan and always will be)
The build is fairly simple- Just some ccbs snapped together and shells slapped on, with some other greebling. I tried to go for the rugged, punching-glove look the original Tarakava had whenever its hand is folded up, and when folded outwards maintain a very reptilian feel, true to the lizard-like nature of the Rahi.
For many unfortunate victims, THIS is the last thing they see if the Sand Tarakava is hoping to simply snatch its meal without beating it to a pulp.
For many others, this is what happens-
Alas, Poor Krux. I barely even knew the guy and the season isn’t out yet.
And here are some other photos I just threw in for other angles;
Feedback and criticism is more than welcomed, it is encouraged. I may or may not do a full-on Sand Tarakava MOC, as I have neither the parts nor the creativity, alas. This literally just came to me in my head today, but hopefully I might be able to do a full one and show it off. For now, however, this arm will just be dragging itself along, attached to what is left of Fire Lord, cast aside alongside his theme, Hero Factory, and placing punching vengeance onto the themes that replaced or outdid it.