Bind the medium-large tungsten dumbbell eyes on top of the shank in the Clouser position, about a third of the way along the straight section, with plenty of over-and-under wraps. Lay a good bed of thread behind them and soak it with head cement — not superglue, which rehydrates and goes crusty in salt water.
Gather 10 to 16 cheap strung saddle feathers, deliberately unmatched in length and shape — tips that do not line up swim better. Bind the bunch in on top of the shank with several tight wraps, sizing the fly so the hook sits in the front third or quarter of the finished profile.
Cut the butts out with big scissors, aiming for some taper, then throw a few wraps over the butts themselves to consolidate them and guard against fouling, and cement the whole absorbent thread base so it soaks in.
Now that there is grip on the shank, come back through the dumbbell eyes with figure-8 and locking wraps and pull them down hard — tying in over the top of other material like this is far stronger than a single tie-in plus glue.
Tie a chunk of blue craft fur along each side as shoulders, tapering the cut butts to smooth the thread runoff, and set them so they split around the saddle tail.
Add a dyed grizzly accent feather along each side, a little shorter than the tail.
Lay Flashabou along each side with the ends staggered, keeping the long strands out of the way, then cement again, forcing the resin into the craft fur butts and the accent feather stems so the underbody sets up robust.
Tie in a plume of fluorescent red marabou by the tip, leaving a small gap in front of the wing so it can open rather than jamming hard against it. Fold it back and wind it as a collar, then trim the waste and moisten it.
Tie the chenille in behind the dumbbell eyes, bring the thread to the front and build up a bulbous head, figure-8ing under and through the eyes and back again. Do not be shy with it — the blocky head creates the turbulence that makes the back end wiggle.
Fold the tag back, catch it in, clean up the head and whip finish twice. Cement the thread wraps and work resin into the chenille as well, so the spaces between fibers fill and the head sets into a solid mass.