This was originally a tarpon fly and I do believe it was created by Lefty Kreh. I could be wrong on the origins. The tarpon fly is usually tied to the back of the hook near the bend. The shank is wrapped in thread.
I tie it more in the common fly style. I tie to behind the eye. This keep the hook point further back in the fly.
One issue I have found with this fly, the squirrel tail is quite slick. I have had many that the hair has pulled out. I now put a drop of super glue on the buts of the hair as I tie it in. This seems to help a lot.