Neptis leucoporos has dark brown to black upper wings with white markings, on the forewings there is a cell line with triangular dots behind them, post-discal spots in spaces 2 and 3 are in the echelon, and discal bands on the hind wings. The underside of the wings is grayish brown with the same markings as the upper side, the dorsum area has a small white band that runs parallel to the hind wing disc band.
Larva: larvae of Neptis leucoporos are yellowish green in color with a series of lateral and ribbon strokes in the dorsal area, thorax area and sides of the 6th and 8th stomach segments shaded with light to dark brown color. Its body is covered by small turbecles, white-tipped spines in the 2nd and 3rd thorax segments, and the 8th abdominal segment. The capsule of the head is light brown with a whitish conical turbecles with a pair of black apical spines, long and pointed.
Pupa: The pupa of Neptis leucoporos is pale reddish brown in color, has a slender abdomen and a large thorax and wingbox extends to the side. The dorsum of the thorax is angled, the head is split at its front edge with a small, tapered lateral knot.