Note: Contested against a published dressing: The source contradicts our shellback outright. The article describes the fly as "basically a variation of the Ray Charles that doesn't have any flashback, and has wire twisted up with the herls to make it more durable" — we store a shellback of clear/pearl flash or thin skin, which the pattern… Source: Fly Fish Food — "Complex Twist Sow Bug" (euro nymph tutorial) — https://www.flyfishfood.com/blogs/euro-nymph-tutorials/complex-twist-sow-bug
Reference Recipe
Hook Scud/curved nymph hook, 14-18
Thread Gray 8/0
Materials
Bead Silver or gray tungsten (optional) bead (1)
Body Gray/tan dubbing, twisted brush (as needed)
Rib Fine silver wire (one strand)
Shellback Clear/pearl flash or thin skin (one section)
How to tie it
Add a bead if using one and mount the curved hook. Start thread and run it to the bend.
Tie in the wire rib and a shellback strip at the bend, tag pointing back.
Build a short dubbing loop, load it with gray/tan dubbing, and spin it into a fuzzy complex-twist brush.
Wrap the twisted brush forward to just behind the bead, building a plump, flat sow-bug profile.
Pull the shellback over the top and rib it down with 4-5 evenly spaced wire turns for segmentation, then helicopter off the wire.
Pick out the belly fibers for legs, build a small head, and whip finish.