The Great Mormon (Papilio memnon) is a large butterfly (120 to 150 mm span) native to southern Asia that belongs to the Swallowtail family.
Papilio memnon females are polymorphic and can take different forms, some of which have tails.

This is the form 'alcanor' of which the females have a tail.
The sides of the abdomen are yellow.
The upperside of the forewing is greyish brown with black veins and streaks.
The cell is red at the base.

Female Papilio memnon form 'alcanor'. Ubud, Bali, Indonesia, 15 October 2011