“The king cobra is the only snake species known to build a nest for its eggs, using coils of dead leaves and other vegetation.”
The king cobra is the world's longest venomous snake, reaching lengths of 10 to 13 feet and occasionally more. It primarily eats other snakes, including venomous species, and is the only snake known to build a nest for its eggs.
By An Nguyen · Published · Updated
Ophiophagus hannahSquamataElapidae
Measured against the 178 species profiled on this site. Each figure is converted to one unit system from the published range on the page, so the ranks are computed, not quoted.
| Measure | This species | Rank here | Exceeds |
|---|---|---|---|
| Body mass | 9.1 kg | #99 of 178#8 of 15 Reptilia | 44% |
| Body length | 5.64 m | #11 of 178#1 of 15 Reptilia | 94% |
| Lifespan in the wild | 20 yr | #61 of 171#7 of 14 Reptilia | 59% |
Closest in body mass
Ranks use the upper end of each published adult range, so they compare typical large adults rather than records, and metrics with no published number are left out rather than estimated. The full table is downloadable from the species dataset, and any two species can be put side by side in the comparison tool.
Browse king cobra photographs—from hatchlings and forest habitat to hunting other snakes and rearing in defense.
Click any photo to view it larger. 8 images available.
Core article
A closer look at habitat, diet, behavior, reproduction, and conservation.
The king cobra (Ophiophagus hannah) is the world's longest venomous snake, native to the forests of South and Southeast Asia. This carnivore is best known for two traits rare among reptiles and unique among snakes: it hunts and eats mainly other snakes, and the female builds and guards a nest for her eggs.
The king cobra's genus name, Ophiophagus, literally means "snake-eater," and that diet defines the animal. Its prey is dominated by other snakes — venomous kraits and true cobras, nonvenomous rat snakes, and even pythons thicker-bodied than itself — with monitor lizards and, less often, small mammals and birds making up the rest.
Hunting relies on scent rather than sight. The king cobra flicks its forked tongue to collect chemical particles and reads them with its Jacobson's organ, following a specific prey snake's trail, sometimes over long distances. It subdues prey with a venomous bite, then swallows it whole, usually head-first; flexible jaw joints and mobile skull bones let it pass prey wider than its own resting head, though it does not "dislocate" its jaw. A single large meal can sustain it for weeks.
Because it is a snake-eating specialist, the king cobra's survival is tied to an intact reptile community. When forest is cleared or people kill smaller snakes, its food supply shrinks along with its habitat.
Adults typically measure 10 to 13 feet (3 to 4 m), and the longest verified individuals approach 19 feet (5.85 m) — longer than any other venomous snake. Weight runs from about 6 to 20 pounds (3 to 9 kg). The body is olive, brown, or black with faint crossbands, and the head is broad with smooth scales.
Like other elapids, the king cobra has fixed front fangs and delivers a large volume of neurotoxic venom, enough to affect the nervous system of large prey. Its warning display is distinctive: it rears the front third of its body upright — often to an adult's eye level — spreads a hood formed by elongated neck ribs (not a permanent flap), and produces a low, growl-like sound made by airflow through the respiratory tract, unlike the higher hiss of most snakes. The display makes the snake look larger while keeping the option to retreat; it is a warning, not evidence that the animal seeks out people.
Despite its name, the king cobra is not a true cobra. True cobras belong to the genus Naja; the king cobra sits alone in Ophiophagus, a lineage that diverged early from other elapids, probably as a specialization for eating snakes.
| Feature | King cobra (Ophiophagus) | True cobras (Naja spp.) |
|---|---|---|
| Genus | Ophiophagus | Naja |
| Typical length | 10–13 ft (up to ~19) | mostly 3–7 ft |
| Main diet | other snakes | rodents, frogs, birds, varied |
| Hood shape | longer, narrower | broader, often boldly marked |
Both are front-fanged venomous snakes that rear and spread a hood, but the shared common name does not make them close relatives. Populations across the king cobra's very broad Asian range vary in colour and proportion, and some recent research proposes splitting the traditional species; this page follows the treatment used by the cited IUCN assessment.
King cobras range across India, Nepal, Bhutan, Bangladesh, Myanmar, Thailand, China, Vietnam, Malaysia, Indonesia, the Philippines, and Hong Kong. They favour tropical and subtropical forest, usually near streams and rivers, and also use mangroves and forest edges bordering farmland.
Suitable habitat is normally a mosaic rather than unbroken deep forest: riparian strips, bamboo, clearings, and plantations beside native vegetation can all supply cover and prey, because moist leaf litter holds the snakes king cobras hunt and streams provide travel routes. Capable swimmers, they cross rivers and enter flooded ground during seasonal movement. Forest edges also bring risk — roads expose moving snakes to traffic, and a snake following a scent trail can enter a garden or poultry pen without seeking people.
King cobras are solitary outside the breeding season and mainly active by day, shifting toward dusk in hot weather. They generally avoid people and are not aggressive by nature; most defensive encounters happen when a snake is cornered, startled, or guarding eggs, and its usual first response to a large animal is to slip away.
During the breeding season males travel widely to track females, and rival males may engage in ritual combat — raising their forebodies and trying to press each other down, typically without biting. This wrestling contest is distinct from a defensive encounter with a predator or person. Approaching for a close photograph removes the distance that normally lets the snake de-escalate.
The king cobra's reproduction is unique among snakes: no other snake is known to build a nest for its eggs. Breeding generally falls between January and April. The female gathers leaf litter and plant debris by looping and pushing it into a mound, often forming a lower egg chamber and an upper layer, then lays a clutch of about 20 to 40 eggs inside. She stays and guards the mound for the roughly 60 to 90 days of incubation, and decomposing vegetation helps hold warmth and humidity around the clutch.
Hatchlings emerge fully independent, strongly banded, and already equipped with functional venom; they receive no care after hatching and begin hunting small snakes and lizards on their own. Growth and survival vary with temperature and food, and only a fraction of a clutch reaches adulthood — so a large clutch does not translate into fast population growth. Wild king cobras live around 20 years.
The king cobra is classified as Vulnerable, with a decreasing population trend across its range.
Deforestation and the conversion of forest to agriculture are the main drivers of decline, cutting both habitat and the prey-snake populations the species depends on. King cobras are also killed out of fear or in retaliation for poultry losses, collected for skins, meat, traditional uses, and exhibition, and struck by vehicles when crossing between forest patches by day. Their large size and specialized diet make them more sensitive to habitat fragmentation than smaller, generalist snakes.
Conservation therefore requires connected streamside vegetation and forest corridors, not just isolated reserves. Trained community snake-rescue networks can reduce deaths of both people and snakes where relocation follows local law and disease precautions, and public guidance should stress distance and professional help over handling. The species' Vulnerable status reflects decline across a large range, not the danger of any single encounter.
Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Squamata
Family
Elapidae
Genus
Ophiophagus
Species
O. hannah
The king cobra is the only snake species known to build a nest for its eggs, using coils of dead leaves and other vegetation.
It is primarily ophiophagous, meaning it mainly eats other snakes, including venomous species and occasionally other king cobras.
It is the world's longest venomous snake, with confirmed lengths exceeding 18 feet.
Although its venom is not the most toxic drop-for-drop among snakes, a single bite can deliver a very large volume of venom.
When threatened, a king cobra can raise the front third of its body off the ground, bringing its head roughly to the eye level of an adult human.
Despite the genus name Ophiophagus meaning 'snake-eater,' the king cobra is not classified in the true cobra genus Naja.
Select a question to reveal the answer.
Adult king cobras typically measure 10 to 13 feet (3 to 4 m) long. The longest verified individuals have reached close to 19 feet (5.85 m), making it the longest venomous snake in the world.
No. Its venom is not the most toxic drop-for-drop compared with many other venomous snakes. What makes a king cobra bite dangerous is the large volume of venom it can inject in a single strike, combined with its size and reach.
King cobras are carnivores that primarily eat other snakes, including venomous species such as kraits and other cobras, as well as pythons. They occasionally eat monitor lizards, small mammals, and birds.
Yes. The king cobra is the only snake species known to build a nest for its eggs. The female gathers leaf litter and vegetation into a mound, lays her eggs inside, and guards the nest until the eggs hatch.
King cobras live across South and Southeast Asia, including India, Thailand, Vietnam, Indonesia, Malaysia, Myanmar, and the Philippines. They favor dense forest, often near streams and rivers, but also occur in mangroves and agricultural edges.
King cobras generally avoid humans and are not naturally aggressive. Most defensive displays and bites occur when a king cobra is cornered, surprised, or guarding a nest.
King cobras are listed as Vulnerable by the IUCN, with a decreasing population trend driven mainly by habitat loss, deforestation, and conflict with humans.
Related animals
