Black and Green Marabou, or with a light olive green body, a Kemsley's Green Marabou. Either way, it is a top New Zealand trout lure pattern for both brown and rainbow trout. The bottom picture shows the same lure once it is wet.
Black and Green Marabou Fly – Trout Streamer Fly – Gary Kemsley

Black and Green Marabou Marabou style flies are now sold in just about every colour.

Jamie McKewen of Mosgiel timed the beat of this magnificent 8lb brown trout for more than an hour before fishing for it. Jamie was fishing in the Maniototo area. Photo courtesy of Dean Whaanga.
Brown Trout – Salmo trutta – Identification and Introduction Guide

Brown Trout Salmo trutta – Colouration, Identification, and Introduction into New Zealand. All the trout.