King cobra

Identification

Adult king cobras of this species are mid-brown with 27–48 pale yellowish bands, each edged with dark grey; the first bands on the neck form chevrons, and the tail end is almost black¹. The throat is bright yellow, sometimes orange. Young snakes have ivory-white bands, even on the head¹. All king cobras have a pair of large occipital scales at the back of the head, which true cobras lack^1,2.

Adults are commonly about 3–3.6 m long³. It is the world’s longest venomous snake, reported to reach 5.5–5.6 m^1,4. The longest ever measured (5.71 m) came from the Malay Peninsula⁵, whose king cobras are now a separate species¹.

Distribution

Until 2024, all king cobras were treated as one species. A 2024 revision split them into four: the northern king cobra (Ophiophagus hannah), the Western Ghats king cobra (O. kaalinga), the Sunda king cobra (O. bungarus) and the Luzon king cobra (O. salvatana)¹. The Reptile Database follows this split⁴.

As now defined, O. hannah lives from the Himalayan foothills of northern India, Nepal and Bhutan, through eastern India (including the Sundarbans and the Andaman Islands) and Bangladesh, to southern and eastern China, Myanmar, Laos, Vietnam, Cambodia and Thailand, probably north of the Isthmus of Kra^1,4. King cobras of India’s Western Ghats are now O. kaalinga¹.

Habitat

In the Indian subcontinent, king cobras are mostly found in forests, including hill forests¹. They are often found near streams in dense or open forest, in bamboo thickets, in mangrove swamps and in farmland next to forest³. In Bangladesh they occur wherever fairly undisturbed bamboo stands and forests remain².

Behaviour

The king cobra is active by day³. Like other cobras, it can raise the front of its body off the ground and spread a hood when threatened². It normally prefers to escape, and it attacks people only when cornered, in self-defence or when guarding its eggs³.

Diet

The king cobra is a specialist snake-eater⁴. It mainly eats cold-blooded animals, especially other snakes, and can overpower large harmless species such as rat snakes, including the Indian rat snake (dhaman), and pythons³. Its venom stuns the nervous system of its prey³.

Reproduction

The king cobra lays eggs⁴. It is the only snake known to build a nest and guard it⁴. The female lays 21 to 40 white, leathery eggs in a nest of leaves, and the heat from the rotting leaves helps to incubate them³. There is also evidence that females can sometimes produce young without mating, which is called facultative parthenogenesis⁴.

Venom and medical significance

The king cobra’s venom is neurotoxic: it attacks the nerves, especially those that control breathing³. Bites cause swelling at the bite site together with paralysis². The World Health Organization places it in Category 2 (secondary medical importance) in India and Bangladesh. This category covers highly venomous snakes that are involved in bites less often, or for which data are lacking². Indian polyvalent antivenom is made against the “big four” snakes, which do not include the king cobra; a specific king cobra antivenom is produced in Thailand². Anyone bitten by a king cobra should go to hospital immediately.

Conservation

King cobras are listed as Vulnerable on the IUCN Red List⁶. This assessment was made in 2012, before the 2024 split, so it covers all four species together^1,6. Their main threats are habitat destruction and persecution by people³. In India, all species of the genus Ophiophagus are listed in Schedule I of the Wild Life (Protection) Act, the highest level of legal protection⁷.

Similar species

The Indian cobra (Naja naja) also spreads a hood, but it lacks the pair of large occipital scales at the back of the king cobra’s head². Adult king cobras are also usually far longer, commonly 3–3.6 m³. The Indian rat snake (Ptyas mucosa) cannot spread a hood and has small loreal scales between the nostril and the eye, which elapids such as cobras lack². In the Western Ghats, the king cobra’s close relative O. kaalinga has pale bands without dark edges¹. These differences are not a safe basis for handling any snake. Keep well away from any snake you cannot identify.

In captivity

The king cobra is a large, dangerous venomous snake and is not suitable as a pet. In India it is protected under Schedule I of the Wild Life (Protection) Act, as amended in 2022, which gives it the strongest category of legal protection⁷. It should never be caught or kept by private individuals.