This is just one of many variations of a scud pattern. Here I use olive and hare’s ear dubbing, with an olive scud skin and mono for the segmentation. A brown permanent marker on the top of the scud back adds some realistic coloration.
These are super successful in spring creeks where there are lots of sow bugs, but you can also tie them in different colors and fish them in tailwaters to imitate freshwater shrimp.