Mount a standard dry-fly hook and start grey thread a third of the way back from the eye.
Cut matched slips from a pair of grey duck quills, pair them with the concave sides together, and tie them in upright as divided wings one shank length tall.
Post and divide the wings with figure-8 turns until they stand apart and vertical.
Wrap back to the bend and tie in a bunch of blue dun hackle fibres as a tail, one shank length long.
Dub a slim body of muskrat grey forward from the bend to the wing. Use half the dubbing you think you need.
Tie in two blue dun hackles behind the wing and take two turns behind and two in front, stroking the fibres back as you go.
Build a small head one eye-length clear of the eye, whip finish and cement.