Thread Grey (head coloured red with a marker) Danville 3/0
Materials
Bead 3.8 mm slotted tungsten (1)
Weight 0.015 lead wire (a few wraps)
Tail UV white marabou (one and a half shank lengths)
Body Pearl chameleon tinsel, spun in a dubbing loop (1 clump)
Head Grey thread coloured red with a marker (-)
Finish Water-based head cement (-)
How to tie it
Mount the size 12 Fulling Mill FM5130 and take a few wraps of 0.015 lead wire. The lead lets you flip the bead over and push it onto the wraps, which both holds the bead in place and makes the fly invert.
Start grey Danville 3/0, a heavier thread than usual, because this is a bigger fly, and lay a base back to where the barb would be.
Tie in UV white marabou about one and a half shank lengths long with a loose wrap and then a couple of firm ones, then bind it back into the bend a little. That rearward tie-down is what stops the marabou fouling on the hook.
Trim the butts, cover them and work the thread back.
Form a dubbing loop round your finger, wrapping round it a couple of times, advance the thread forward and hang a dubbing spinner in the loop.
Grab a clump of pearl chameleon tinsel, pinch as many fibres as you can into a dubbing clip and trim them to about a quarter of an inch.
Open the loop with your fingers, insert the clip, pull tight and spin the loop up.
Hang the thread over the cradle and wrap the corded loop forward with the rotary vice, sweeping the fibres back as you go so you do not trap too many, then secure with a couple of wraps and trim.
Colour the thread red with a quality marker, sweep the fibres back and take wraps of the now-red thread at the head. Red reads as gills on a baitfish imitation; orange works too.
Five turn whip finish and trim.
Brush the fibres out with a dubbing brush, then give the body a haircut with long fine point scissors, tapering it.