The king cobra's scientific story begins in 1836, when Theodore Cantor first described it under the name Hamadryas hannah. In 1864 Günther proposed the genus name Ophiophagus, which means snake-eater. The animal is not a true cobra, because it differs from the Naja cobras in several body features, and genetic work links it more closely to mambas. A 2024 revision then studied 148 whole and five skeletal king cobra specimens, and it supported its findings with a recent molecular phylogenetic analysis, which uses DNA to work out how animals are related. Mitochondrial DNA analysis of king cobras in Thailand had suggested a deep split between northern and southern specimens. The revision also designated a neotype, a new reference specimen, for the original name Hamadryas hannah Cantor, 1836.
Under the revision, the name Ophiophagus hannah is now restricted to king cobras from eastern Pakistan, northern and eastern India, the Andaman Islands, Indo-Burma and Indo-China, south to central Thailand. The name Ophiophagus bungarus was revived for king cobras of the Sunda Shelf, including the Malay Peninsula and the Greater Sunda Islands. Two new species were also described: Ophiophagus kaalinga in the Western Ghats of India and Ophiophagus salvatana on Luzon in the Philippines. Scientists now recognize four king cobra species, and a key is provided to tell them apart. King cobras live from northern India east to southern China and south through the Malay Peninsula to western Indonesia and the Philippines.
Why does the count matter? As of November 2026, the IUCN has listed king cobras as vulnerable but has not assessed the risk of the new individual species. Cutting down forests in Southeast Asia has destroyed the homes of many king cobras.
The make-up of king cobra venom, and how it acts, varies a great deal between snakes from different places. Venom is a complex mixture of proteins encoded by several families of genes. The neurotoxins in it act on the nervous system, especially the signals for breathing.
Field work keeps filling in the rest of the picture. In Thailand, scientists implant radio transmitters in king cobras and find each snake by triangulation, and in one study in northeast Thailand they tracked seven king cobras for an average of about 650 days. King cobra movements increased in forest and tended to decrease in agricultural areas. The snakes spend almost a quarter of their time up in trees or bushes. The king cobra is also the only snake that builds a nest for its eggs. Why a female stays by her nest is not known for sure: she may protect it, or she may help keep it at the right temperature. The tree of king cobras was redrawn in 2024, but the nest, the venom and the movements are all still being studied.
Words to know
- neotype: reference specimen
- phylogenetic: family-tree
- mitochondrial: inherited from mothers
- specimens: samples studied
- triangulation: finding by angles
