A very simple fly. This is just a standard black pennel with just one difference. The body is made from blue floss instead of black. You can use fur instead of floss if you prefer.
A good fly for me for both browns and sea trout here in Ireland but I guess it will do the business back in the UK too. I fish it on the tail with a bushier pattern above it. Sizes ranges from 8 down to 14 and I use heavy gauge hooks in case a salmon takes a fancy to it. For me it is a fly for a dull day and I sometimes pair it with a Bruiser Bumble.
While I am on about Pennels, I remember years ago making up a variation of the standard fly by adding a hot orange cock hackle behind the black one. This made a great looking fly, a sure fire winner I thought. Wrong! Despite giving it a try a few times it failed to rise a single fish. Just goes to show how picky the trout can be.