This fly is tied on a size 10 hook represents the cased Caddis. The body is spun deer hair that is then clipped to shape. The head of the fly is white wool which suggests the head of the Caddis grub poking out.  To add the final bit of realism cock pheasant tail fibers are tied into the wool to suggest the legs of the insect.  On rivers fish this pattern as part of a team with a more weighted fly on the point and this on one of the droppers.  On lakes fish it as part of a team cast into the shallow margins.  Suitable for use all season.