I finally have managed to enter a contest! And here is the entry:
Jaller’s Hahna crab, seen in the Toa Mahri mini-movie and in the Jaller Mahri set. It has a working GWP-styled Cordak Blaster, and the legs are poseable. Total part count is 38 pieces, putting it at a manageable price for an actual Gift With Purchase set. Some parts may not be available in the colors I used, but they can be replaced with minimum effort.