Round rubber legs Black ostrich herl (1 strand (eyes))
Craw Dub (SLF) To match crayfish (Body and head)
Cheap yarn To match body (Underbody)
UTC wire Ginger (match hackle) (1 length (rib))
Whiting Euro saddle hackle To match body (1 feather)
How to tie it
Pre-make the claws: cut small squares of 2mm foam, thread a barred rubber leg through the edge with a large sewing needle, add a drop of superglue, and trim the foam to a triangular claw shape at the vise.
Start the thread near the eye of the bent-shank hook and figure-eight lead dumbbell eyes on TOP of the shank so the fly rides hook-point up; add superglue over the wraps to stabilize them.
Reposition the hook so the main shank is horizontal, lay a thread base to the rear, and tie in a small clump of root beer crystal flash at the bend, trimmed about one body-length long (antennae).
Cut a thin strip of Thin Skin, trim a V in its end, and tie it in at the rear on what will be the top of the fly (the underside of the hook), wrapping back to the crystal flash tie-in.
Dub a small ball of Craw Dub at the rear to cover the tie-in point.
Tie a strip of black round rubber across the shank, pull one strand to each side, and wrap back so the dubbing ball spreads them out as eyes.
Trim the pre-made claws and tie one on each side, foam tips even with the back of the crystal flash; secure the rubber arms back past the hook point so the claws stick straight out to the sides and can't foul the point.
Build a fat underbody with cheap yarn matching the body color, working a small head in between the claws and eyes.
Dub the head area around the base of the claws, then tie in ginger UTC wire (short end forward, folded back and re-bound so it can't pull out) and the Euro saddle hackle at the front.
Dub the rest of the body rearward, palmer the hackle back over it, counter-rib with the wire to lock the hackle in, pull the Thin Skin forward over the back, tie down at the head, whip finish, and comb out the dubbing for a shaggy look.