I've been trying to find a recipe or tying instructions for a fly called Big Nasty. I believe it was originally tied by Kevin Howell, but I can't find anything. When I try searching the internet I get lots of results for RIO fly lines (also called Big Nasty), but I can't find anything definitive for the fly. I'm not confident enough in my tying ability to try to reverse engineer it from a picture. Here's a picture of the fly. I'll also attach one as a file in case embedding it in the post doesn't work well. Any help would be greatly appreciated. Thank you.