Start the rusty brown thread and take it well around the bend of the curved hook.
Tie in three peacock sword fibers (sword, not herl) as a stubby tail about 4mm long, trimming the excess.
Prepare the vinyl rib: melt the tip into a small bubble with a lighter and pull it flat for a low-bulk tie-in point, then catch it in with the curved side facing up.
Take the thread up to the eye and throw in a half hitch to park it.
Wrap the vinyl rib forward in touching turns, pulling the first couple of wraps tighter over the tie-in point, all the way to about one eye-length behind the eye; secure with tight wraps front and back and snip.
Build a small thread taper ramping back to the front of the body so the wing will lie back instead of pointing skyward.
Stack a small, sparse clump of deer hair, measure it to about the back of the body, and pinch-wrap it in at the front. Let the butts flare upward.
Take a couple of medium-tight wraps rearward to lower the wing angle slightly, then trim the flared butts elk-hair-caddis-style, leaving a stubby head.
Whip finish behind the eye and put a drop of head cement or UV resin on the underside threads, keeping it out of the eye.