This is a Griffith's Gnat. I used brown hackle instead of grizzly. I don't know why I did that.
Below is a beadhead Clouser Swimming Nymph. I used possum dubbing for the abdomen. Looks like there's a big gnarly guard hair sticking out of that!
Below is another idea for a crayfish pattern. It seems ok, but still not exactly what I'm looking for. Getting closer, I think.