Designed by Mike Mercer of Redding, CA. as a caddis pupa pattern. The curved hook provides a good natural profile. There are usually three color variations to this pattern: Olive (for cloudy days and the fall) , Caddis Green (for the Spring Mother's Day hatch), and Amber (a good choice year round). The fly shows distinct contrast with a darker back and a lighter dubbed body.The back is generally Turkey Tail but Mike has also used Marabou, both which give a natural hairy appearance. The use of Turkey Tail also provides a mottled coloration. The Z-lon is tied small to represent a premordial wing that is just emerging. A collar of Antron, in front of the wings, is used at times to provide the distinction of the emerging caddis. The head can be peacock herl or marabou. A good mid-day pattern of a pupa, fish it deep under an indicator with a rising action. This is the transition where the larva starts to transition as an adult. The caddis pupa releases from the bottom substrate and starts to rise through the water column. Since you use it the fly in moving water, a bead can be useful in getting the fly to the closer to the bottom of the water column. The fly has also been used in stillwater conditions using short strips.