Mount hook, lay a thread base. Tie in a small stacked bunch of moose body hair at the bend for the tail. One shank length, stiff and dark.
Tie in 2-3 peacock herls, twist into a rope, and wrap the rear third of the body.
Tie in red floss and wrap the middle third, a clean, smooth band between the peacock sections.
Wrap more peacock herl for the front third. The two peacock bands should match, framing the red evenly.
Cut, clean, and stack two clumps of white calf hair. Tie in upright and divided with figure-8 wraps. Calf hair fights you; take an extra wrap and a drop of cement at the base.
Wrap two brown hackles, 2-3 turns behind the wings and 2-3 in front, packed dense. Wulffs carry heavy hackle by design.
Build a neat head, whip finish, cement.
Substitutions
Body instead of Peacock herl & red floss: Peacock Ice Dub & red Ultra Wire — Much more durable than natural herl; Peacock herl & red thread wraps — Skip the floss, use your thread
Tail instead of Moose body hair: Brown bucktail — Similar stiffness, widely available; Elk hair — More buoyant than moose; Coq de Leon fibers — Stiff and durable
Wing instead of White calf hair: White poly yarn — More visible, turns it into a Royal Trude variant; White calf body hair — Finer, easier to divide
Other versions
7 more in the app: Fischer's Flies, Joe Penich, Fly Fish Food Tie, variant 1, Fly Fish Food Tie, variant 2, Barbless, Chartreuse, Wulff Royal.