Mount the rear (stinger) hook and lay a thread base. Bind a rabbit strip on top so it trails a full shank length past the bend, hide dull-side down so it undulates.
Lash a length of stiff wire (or braid) to the rear-hook shank and whip it off; this becomes the articulation joint.
Mount the front hook, bind the free end of the wire firmly along the shank so the rear rides close with a small gap, and secure with wraps and glue.
Build the body: dub a dense brushed-dubbing base up the shank, brushing the fibres out after each section to make a fat, buggy profile.
Tie in hen or rubber fins low on each side to splay outward like pectoral fins, the sculpin's signature.
Slide the sculpin helmet on and seat it firmly at the head; the weighted, forward-cupped helmet is what makes the fly nod nose-down and rock up on the pause.
Whip finish behind the helmet, cement, and brush the collar back into the helmet.