Euthalia aconthea has dark brown upperwings with wide, indistinct post-discal bands on both wings in males. The inner edges of the band are whitish in color, the wings give off a dark purplish tinge when viewed from the side. The female butterfly is bigger and the color is paler, the white spots on the front wings are bigger and clearer. The undersides of the wings of this species are paler with a series of submarginal black spots on both wings. The proboscis is lime green.
Larva: Euthalia aconthea larvae when hatching have a yellowish green body, the capsule of the head is pale yellowish brown. Its body has ten long, yellowish, fleshy dorso-lateral protuberances, and black setae originating from these protuberances. At the next instar ten pairs of protuberances extend significantly, each one projected horizontally with many branching spines. There is a white patch on the dorsum between the protuberances.
Pupa: Euthalia aconthea pupae are green with brown spots on each corner. The color will change to dark when it will emerge into a butterfly, the length of the pupa is about 18-20 mm.