Saw this pattern mentioned on another forum; did an interweb search and found it in Pequegnot's French Fishing Flies: Patterns and Recipes for Fly Tying. Original called for condor or eagle quill body, neither of which is legal in the U.S. so I subbed biot. Note the wings are tied in vertical orientation, Killer-style.

hook - Dai Riki 300 #10
thread - Danville 6/0 brown
body - turkey biot dark brown
wing - brown mallard breast
hackle - brown


Regards,
Scott