This is a very productive dry fly here in our local streams. It was designed by Tony Biggs and you can probably find it in every fly box in South Africa. It is a wide hackle dry fly with long trailing legs to create the impression of movement. It presents beautifully and if tied correctly settles on the water as light as a feather.
RAB stands for Red Arsed Bastard
Here is a great Step by Step by Tom Sutcliff.
HOOK: Light wire dry fly hook with a wide gape
TAIL: Cock hackle fibres or CDL
BODY: Stripped Peacock quill
HACKLES: Ginger saddle hackle and CDL.
LEGS: Squirrel tail fibres
This wild river Brown loved the RAB