Hypolycaena erylus has dark purple upperwings with large black circles on the forewing discs in males. The female butterfly has brown to dull gray wings with dark brown stripes on the post-discal front and rear wings, two large black spots on the marginal area and a white crown in spaces 1b and 2. The undersides of the wings of both sexes are pale greenish gray with a reddish brown stripe on the post discal portion of each wing. On the hindwings there are 2 black spots with an orange crown, one of which is smaller. This species has 2 black tails with a white tip on the veins 1b and 2, the tail on the veins 1b is longer. The legs are white with black stripes.
Larva: Hypolycaena erylus larvae that have just hatched have a pale yellowish brown body with dark lateral bands on each side of the body, the head is yellowish brown, 1.4 mm long. Its body is covered by rather long and black setae. Larvae on subsequent instars are lime green with a more pronounced reddish-brown stripe on the lateral dorso.
Pupa: Hypolycaena erylus pupa is pale green in color with small dark green spots on the surface. Length is about 13 – 14.5 mm.
