Slide the small orange glass bead onto the hook and let it ride loose for now; start the thread and wrap around the bend.
Tie in a short tuft of webby saddle-base hackle for the tail so it kicks slightly downward off the bend.
Tie in the x-small silver wire, then the olive Scud Back strip, at the bend. Materials go on in reverse order because they come back over the top later.
Dub a deliberately thick, chunky body forward: fill the rear of the shank, hold the bead where you want it (about mid-shank, the 'egg'), cross the dubbing strand over the top of the bead, then dub the front section to the eye. Half-hitch.
Now, before the shellback goes on, brush the dubbing out aggressively downward; this is the easiest time to pull the legs out.
Pull the Scud Back over the top with just enough tension to seat it and tie it down at the front.
Rib forward with the silver wire for segmentation: about three turns behind the bead and two or three ahead of it. Tie off.
Pull the materials back, whip finish and add a dab of head cement.
Trim to shape: leave the picked-out fibers long underneath as legs, and clip the sides at a slight angle just above the hook point so the scissors clear the shank.