Elzunia humboldt has a wingspan of about. This species is quite variable depending on the subspecies. The uppersides of the wings are black, with a series of small white spots on the margins. At the base of the hindwings usually there is a broad yellow band, while in the middle of the forewings usually there are one or more whitespots. The undersides of the wings have a similar pattern to the uppersides, but the basiccolour is reddish instead of black and the hindwings usually have two series of white spots.
E. h. humboldtE. h. bonplandiiE. h. cassandrina Srnka, 1884 E. h. regalisE. h. albomaculataE. h. joiceyiE. h. atahualpaFox, 1956E. h. judsoni Fox, 1956