Hook: Size 2, 4, 6; 2X Long, or Streamer hook, sizes 2-6
Body: Flat Silver Tinsel
Rib: Oval Silver Tinsel
Wing: Yellow Bucktail with Red Bucktail Streak Through Center
This pattern is listed in Mel Marshall's, Steelhead, Copyright 1973 as one of the top two dozen Winter Steelhead flies to be counted on. He writes that this fly is very good in slow-moving water. From what I have read about the Mickey Finn, it was originally a streamer fly known as the "Red and Yellow Bucktail" developed in the early part of the 20th century. It became very popular in the 1920's and 1930's and became known as the "Mickey Finn" because, like the drink of its namesake it was very deadly. That, at least, is the story I read.
The fact that this fly is tied on a salt water hook actually shows it versatility. I have used this fly successfully in the salt for chum salmon, and as a smaller fly for trout and pinks in fresh water.