Getting somewhere now.... Its a mix of impressionistic and realistic fly tying methods. Mostly realistic with the rabbit zonker hair to add movement when static. Based on a speckled crab (arenaeus cribrarius)- the most common swimming crab in surf zones and sand flats in the tropics and sub tropics world wide.
I had no sand for the epoxy bits so I mixed talcum powder (baby powder) with umber ochre paint pigment in with the epoxy.
His real trick is how he swims. I crimped the polar fibre legs so you can manipulate where they bend. The back swim fins are pressed flat and crimped close to where they are tied on the hook. The claws are laid wet. They stay in shape and are hardy as hell.
Dumbell eyes and quite a bit of lead under the hook shank to balance the dumbells so it sinks in a balanced position.
Oh, and finally some shale, cinnamon, black and pink permanent marker (crabs always seem to look a bit pinkish).