I call these the Replot rodent and I've tied these specifically to be fished at one place on this island for the spring time. There is an area just north of where I live that probably has the best wading spawning grounds I've ever had the privelage to fish along, and is one of the few places that I have seen plenty of water vole activity due to the submerged reed beds and root system there.
This one has a natural fox zonker strip for a tail and a decent thick collar of natural deer hair with several strands of bronze FFF Krinkle flash tied on. The head is a combination of tan and grey spun deer hair trimmed loosely to retain some water but to also push a lot of water through those first couple of strips on the surface. I've bugbonded the front 8mm of deer hair around th hook eye to give a bit of rigidity to it as well.
This one is much the same design but has a black rabbit zonker tail instead. Both are around 150mm in length. The collar on both have been spun forward so the fur curves forward.I then pull the fur back and tie over that which allows it to be spread outwards which will give the flies fur extra movement.
A mate of mine had a couple of these off me last year and has had great success catching some nice Browns with this same fly.Infact they were so effective I've tied several more in varying length for him to take to New Zealand this year.