Pinch the barb on a size 4 salmon or streamer hook and lay a base of black 140 denier thread back to the start of the bend. The heavier thread handles the fat chenille thorax and the hook's turned-up eye.
Tie in a fair-sized clump of red saddle hackle fibers for the tail, a hook gap long or a little shorter, and check the position before locking it in. If the fibers start spreading around the shank, throw a wrap up under the back of them. Snip the butts so they do not leave a bump under the floss.
Build thread wraps over the back half of the shank to thicken it and get a little taper under the floss body.
Catch in the orange floss up front, wrap it back to the tail and then forward again for at least two layers, since floss goes translucent when wet; add more passes if you want it deeper. Tie it off in front.
Tie in small purple chenille and wrap the thorax like a football: one layer forward, then a couple of open wraps back before you reach the front, then forward again over the top so the middle is fattest. Small chenille wrapped in layers gives a shape a medium never would. Catch it off with a couple of extra wraps.
Strip a few extra fibers from the underside of two badger saddle hackles so they will not flare too high, then lay them on top with a couple of loose wraps and check the angle before locking in; aim for about 45 degrees. Snip the butts.
Tie in another badger hackle by the tip, spreading the fibers to make a tie-in point, take two or three fairly tight wraps and snip the tip off. Take three or four turns of hackle, and add another if it looks too sparse, then catch it off and snip the excess.
Pull all the hackle fibers back at once and take thread wraps over the front of them so they sweep rearward along the body.
Build a big streamer head, whip finish, and put a drop of head cement on it.