Harry and Elsie Darby, the famous fly tiers of Roscoe, New York,
made popular this fly that Harry said was created at his request by
"Percy Jennings, an amateur fly tier from Cold Spring Harbor, known
among anglers for the time he caught a 3 1/2 pound brown on a backcast."
The Rat-Faced McDougal was originally tied with grizzly-hackled-tip
wings, but Harry wrote in his book Catskill Flytier
that white calf-wings were "more visible, just as effective." He never
mentioned the fly's tail, but I would be tempted to use white or tan
calf tail for it, though I've stuck with Harry's ginger hackle fibers
Hook: Standard dry fly, sizes 16 to 10 (the hook
shown is a Gamakatsu F 13).
Thread: White 8/0 or 6/0 (I prefer 3/0 because it really
secures the hair wing); for the spun-hair body, gray size-A rod-winding thread.
Tail: Ginger hackle fibers.
Body: Spun and shaped deer or caribou hair.
Wings: White calf tail.