So here's how to make a crab quickly.
Tie in some marabou at the bend and wrap up around so it points upward.
Tie in some rubber legs so they point straight up.
Wrap some .035 wire from a point opposite the hook point all the way to the eye, saturate with glue then cover with floss.
Form a loop and bring the thread forward.
I use a gallows to hold the loop, it makes life easier, comb out some EP or similar fibers and insert in the loop keeping them as parallel as possible and spin the loop.
Palmer the loop forward while teasing the fibers back so you don't wind over them, tie off at the head and tie in some rubber legs, whip finish.
Tease out the fibers and comb them out into a flat shape, then put UV acrylic along the hook top and bottom to hold fibers in place.