Permanent marker Brown or black permanent marker (For eyes)
How to tie it
Build the rear section first on a shank, crank a cheap size 16 curved nymph hook in the vise and snap the point off, so all you keep is the shank. Start olive 70 denier at the back and tie in small gold wire for the rib.
Pull a half-inch clump of light olive marabou off the stem, tie it in at the rear, advance the thread to the eye, then twist the marabou into a rope with hackle pliers and wrap it forward. Twisting makes the fibres flare out into a fuzzy, breathing body rather than lying flat.
Counter-rib the gold wire forward, wiggling it as you go so it slides between fibres instead of trapping them, helicopter off the excess, whip finish and trim the rear body short. Tied on a plain hook this rear half is a perfectly good damsel on its own.
Move to a size 14 Daiichi 1120 scud hook and lash on burnt mono eyes near the front. Melting your own from 6-8 lb mono lets you dial the eye size to the hook. Damsel nymphs are all eyes, so this is the detail that sells the fly.
Tie in a short piece of 2-4 lb tippet, thread the rear shank onto it, fold it back and lock it down with loose enough wraps that the tail section swings freely. That flop is the whole pattern. A swimming damsel's abdomen whips side to side.
Tie in light olive scud back on top for the wing case, then wrap UV Straggle forward to just behind the eyes, over the top of them, back underneath and around so the eyes are collared in fibre. Trim the top flat and pull the scud back over, securing behind and then in front of the eyes.
Whip finish, tidy the head, and touch the mono eyes with a brown or dark Sharpie. That last step is more for the tyer than the fish, but it finishes the profile. Small, leggy up front, and loose at the back.