The species was previously confused with H. freycineti, which is restricted to Papua Barat Province (western New Guinea), Indonesia. The two species differ primarily in colour pattern, which provides the best means of separating the various members of the genus. Both species have a profuse covering of brown spots with a large black or brown ocellated marking on the middle of the side, just behind the head. The spots of H. michaeli are generally denser, larger, and distinctly polygonal, remarkably similar to the spots of a leopard. In contrast those of H. freycineti are round to transversely elongate and are darkened at regular intervals to form 8-9 bars or saddle-like markings (including those on the tail). The difference in spot pattern between the two species is particularly evident in the head region. In addition, H. michaeli possesses a vivid ocellate black spot behind the head, whereas the black spot of H. freycineti is generally not well defined. Comparison of the mitochondrial ND4 gene also supports the species-level separation of these species.