Mount hook, tie in the shellback strip and wire rib at the bend.
Dub a gray body with plenty of guard hairs, and keep it FLAT and wide rather than round; sow bugs are flattened top to bottom, and that's what separates this from a scud.
Pull the shellback over, counter-wrap the rib in 5 turns.
Pick out the dubbing along both sides for legs.
Whip finish.
Substitutions
Body instead of Gray dubbing with guard hairs: Gray Sow Scud dubbing — Purpose-built for this; Muskrat dubbing — Natural gray with guard hairs
Shellback instead of Clear plastic: Clear Scud Back — Standard scud/sow bug shellback; Thin Skin (clear) — More durable