Phalanta phalantha has dark orange brown with black spots and markings forewings. The forewings have two dark stripes within the cell that form an irregular point of the cell. The undersides are pale orange with a few spots and black streaks, the submarginal and postdiscal areas have a purple luster when viewed from the side.
Larva: larvae of Phalanta phalantha are cylindrical, yellowish brown with a green base color. It has long, branched horns in yellowish brown in the dorso-lateral, lateral and sub-spiral regions. The capsule of the head is brown.
Pupa: Pupae of the Phalanta phalantha are green to yellowish green in color, have small silver horns tipped red on the dorso-lateral portion, two silver patches along the edge of the wing cushion.