Like the Big-eyed bugger, it contains a lot of very mobile marabou. It has the snap-on weighted head that makes it a very much weight forward fly and it dips and dives like a wounded fry when retrieved slowly. Fish on either a floater or sink-tip line, with a leader of only 4 to 5 feet. Cast at an upstream angle, give the fly time to sink, then retrieve with very irregular strips and include slight rests, and remember to vary the strip distance and speed.†
Like the Big Eyed Bugger, not just a river fly, but effective on stillwaters as well.