The Green Machine is built on the chassis of a traditional pheasant tail nymph with added features that make it a workhorse attractor pattern. Although it was designed to imitate a mayfly, this fly is a chameleon of sorts and can pass as a caddis, smaller stonefly, a scud, and even a damselfly larva. 

A gold tungsten bead gets this fly down fast and the flashback and wire ribbing add attention-grabbing elements to an already buggy fly. The real magic comes from the generous CDC collar, which gives the Green Machine lifelike movement, while mimicking the air bubble that forms around emerging insects.