Hard to tell from the picture, but it looks similar to one I tie which is a take off of Stalcup's Crazy Dad and Gierach's Mudbug (from his book "Good Flies"). This is certainly a simpler, more impressionistic pattern.
Hook: straight eye streamer hook
Thread: 3/0 brown
Weight: 1/30 oz lead eyes
Tail / antenna: 4 strands root beer Krystal Flash, approximately shank length
Body: amber Polar Chenile
Legs / claws: 2 strands rubber hackle, approximately shank length
Wing / back: brown bucktail

Mudbug.jpg