CK Nymph by Chuck Kraft. Chuck developed the CK Nymph in 1961. I was featured in Field and Stream in 1971 in an article titled, Wonder Nymph: Deadly Anytime Anywhere written by Sam Slaymaker II. You can read more about the article here
easterntrophies.com/who-was-c...
This fly is deadly on Trout, Bluegill, Crappie and as I have discovered more and more.....Smallmouth Bass. I have been tying it in larger sizes for Smallmouth and having very good success on tough days when the fish aren't very active.
CK Nymphs are available at easterntrophies.com along with CK Nymph Kits which give you all the materials to tie the fly just like Chuck used to.