Note: This recipe has not been verified against a documented source, or disagrees with one. Treat the materials and steps as unconfirmed.
As tied by tightlinevideo
Hook 2X-short emerger hook (Dai-Riki 125), 18-24
Thread Dark brown 16/0 Veevus
Materials
Tail/Shuck Brown or ginger hackle fibres
Body Beaver dubbing, olive
Flash One strand of Flashabou
Wingcase/legs Wood duck
Thorax Natural beaver fur
How to tie it
Mash the barb and secure the hook firmly in the vise jaws.
Start the thread on the shank behind the eye and take a few wraps rearward, then snip the tag.
Strip about 8 brown or ginger hackle fibres with tips roughly aligned, snip off the curly ends, and tie them in on top of the shank as a trailing shuck, binding them well down into the bend.
Advance the thread to halfway between the hook point and the barb and snip the shuck to about a hook gap in length.
Strip any guard hairs from a small pinch of olive beaver, dub the thinnest noodle on the thread, and wrap it forward from the base of the shuck to build a tapered body, ending with the thread at the hook point.
Tie a single strand of Flashabou on top of the shank, secure it back to behind the eye, and snip the excess.
Strip 8-10 wood duck fibres (tipped black and white), snip off the curly ends, return the thread to the hook point and tie the butt ends on top of the shank almost up to the eye for the wing case and legs.
Dub a short, thin noodle of natural beaver for the thorax, starting just back from the eye, wrapping back to the hook point and then forward again.
With the thread behind the eye, fold the wood duck over and secure it, then pull the Flashabou over, lock it down, fold it back and wrap over it, and snip the excess.
Separate the wood duck butts into two equal clumps, pull one down each side of the fly and lock them back with a few thread wraps, without building bulk.
Finish the head with a short 4 or 5 turn whip finish and cut the thread.
Pull the wood duck butts back and trim them to form legs just slightly longer than the thorax.
Other versions
1 more in the app: Consensus of InTheRiffle, Anglers All, Marty's Bench, East Rosebud, Tim Cammisa.