A relatively new streamer pattern developed in the 80’s by David Train, funny enough he used his cats whiskers to tie the fly hence the name.
This is rated as one of the most popular streamer in the UK still waters today.
This fly rides hook point up so no worries about snagging on the bottom.
Fish on a sinking line with a long leader and fish slow.
The chartreuse works well just before the fish come on to the spawn at the beginning of the colder months.