Pheasant tail fibers (antennae) Golden or ringneck
Heavy monofilament (eyes, ends melted to balls)
Swiss straw (carapace) (or scud back)
Yarn (body) To match fly
Red squirrel tail (claws)
Lead wire (underbody weight) (~.030")
Pheasant tail fibers (legs)
Larva Lace or Swannundaze (tail segmentation) Matched to fly
How to tie it
Give the shank an even coat of thread; materials go on in sequence starting at the front (crayfish are tied to swim backward).
Antennae: tie in two pheasant-tail strands, one on each side of the hook so they splay apart.
Eyes: take heavy mono, melt each end into a small ball with a lighter, let it harden, and tie the eye-stalk in with tight wraps (mono is slippery); trim the ends.
Invert the fly (a rotary vise helps). Tie in the Swiss-straw carapace strip so it can be pulled over later.
Split a strand of body yarn in half; tie it in and make a small ball of yarn at the nose to help spread the claws, then tie it back out of the way.
Claws: from red squirrel tail, tease out the short hairs, size a wispy bunch, and tie one claw to each side of the hook (all fibers on one side each), taking a couple of gathering wraps at the base of each; trim the butts at an angle tapering toward the eye.
Weight/orientation: lash a length of ~.030" lead wire to the underside with the slack coming off the bend side, wrap the lead around just the back half of the shank, fold and trim it alongside so the fly rides hook-point up, and lash it down; smooth the lead ends with your thumbnail.
Legs: tie in two pheasant-tail strands crosswise so they stick out each side, advance the thread, and tie in a second pair further back.
Twist the body yarn slightly and wrap it forward through the legs and over the lead so no lead shows, laying wraps side by side; tie off.
Pull the Swiss-straw carapace over the back and tie it down, then rib the tail/back with color-matched Larva Lace or Swannundaze for segmentation; whip finish and cement.