Eyes Small-to-medium plain lead dumbbell eyes (1 pair)
Body/shell Beige or tan E-Z Body / Flexo tubing (small, about 1/8 to 3/16 in) (1 section)
Legs & claws Tan micro (ultra) velvet chenille, pulled through the tubing (several)
Crab eyes Small black mono or EP crab eyes (1 pair)
Coating UV resin or Softex to seal the shell (-)
How to tie it
Tie the small lead dumbbell eyes on top of the shank near the hook eye (fly rides hook-point-up); add superglue.
Slide a section of tan E-Z Body tubing over the hook; tie it down at the rear to form the crab shell and flatten it into an oval.
Pull short pieces of tan micro chenille through the tubing to form six legs and two splayed claws at the front, securing each; add the small crab eyes at the front.
Trim the shell to a small oval carapace and seal/coat it with UV resin for durability.