Mount hook, tie in dumbbell eyes on the BOTTOM of the shank near the eye. When the weighted side flips down in the water, the hook point rides up, which is exactly what you want on grassy flats.
Tie in EP Fibers in crosswise clumps along the shank, figure-8ing each clump so it stands perpendicular. 4-5 clumps builds the disc.
Add knotted rubber legs between clumps, 2-3 per side, and two slightly longer EP clumps at the rear for claws.
Brush all the fibers out flat with a velcro brush, then trim to a rounded crab silhouette. Flat and wide, like a poker chip with legs.
Apply a drop of UV resin at the head area to lock everything down.
The finished fly should land softly, sink hook-point-up, and sit flat on the bottom.