This is my shrimp pattern. It gets its name from the material that I use for the shell. Some people use plastic baggies, but I use scud back, a pliable material made for scud flies.
Materials, in order that they're placed on the hook:
Hook: size 4
Thread: color to match pattern, here 6/0 rust
Eyes: bead chain
Antennae: rainbow krystal flash and tan marabou
Ribbing: fine copper wire
Body: ice chenille
Shellback: scud back, orange
The only tricky part is attaching the scud back. It's tied in at the eye and pulled down to the bend over the eyes, and then secured in place with the copper wire. Wrapping the wire is the last thing that's done, securing it at the eye of the hook with the thread that's there waiting for it.
Another color combo that works well with this is olive. And when the shrimp are high in the water column or just in the surface film, the bead eyes can be replace with mono eyes like those used for damsel nymphs and the wire can be replace with 3/0 thread of the appropriate color. I've taken many weakfish with this fly, but I've put it here in the bonefish/tarpon archive because I'm told that it seems to be made for bones. Someday I hope to test it out on a few.