Consensus of Marty's Bench and SanJuanRiverFlytyer
Materials
Tail Pheasant tail fibers
Back Pheasant tail fibers
Abdomen Tying thread
Wing case and legs Antron, split
How to tie it
Start fine thread (8/0 or 70 denier, light olive) and take it to the bend, laying one layer of thread for the light belly colour.
Tie in pheasant tail fibres with the tips even for the tail, keeping the brown on top; keep the tail fairly short (tail, abdomen and thorax each about one third of the fly).
Wrap the thread forward in touching turns to make the abdomen, pulling the pheasant tail fibres over the top as a dark back and binding them down at the forward third.
Optional: tie in a strand of Mirage flash centred on top.
Tie in Antron split into two halves, folding each half back one turn on its side to form the legs and wing case.
Build the thorax: a thread ball on size 18 and smaller, or a little thin superfine dubbing on a 16.
Whip finish with a couple of turns to keep the head small and trim the legs a little longer than the abdomen.
Other versions
2 more in the app: As tied by Eli Gonzales (size 22), As tied by Hopper Juan Ramirez (variation on the OG).