The king cobra is a snake respected above all others, and for good reason. It is by far the largest venomous snake in the world, packs enough venom to kill an Asian elephant with a single bite to the trunk, and possesses a rare intelligence that scientists are only beginning to understand. Learn all about this amazing animal in our "Cobra Fact File." (For information about how this snake is put together, visit our Tour a King Cobra feature.)

- Relatively Speaking

- The King's Dominion

- Uncanny Intelligence

- Lovestruck Snakes

- A Protective Parent

- Princes and Princesses

- The Cannibalistic Cobra

- Ready to Strike

- Packing Poison

- A Growling Moan

- King Cobra Culture

- A Vanishing Species

Information provided in this feature is based in part on Venomous Snakes of the World by Mark O'Shea, Smithsonian Answer Book: Snakes by George R. Zug and Carl H. Ernst, and correspondence with herpetologist Romulus Whitaker. Image Credit: Courtesy of Sandesh Kadur / www.sandeshkadur.com

King Cobra (Ophiophagus hannah)

Relatively Speaking

The king cobra belongs to the family Elapidae, which includes cobras, kraits and coral snakes — all highly venomous species that share the common trait of relatively short, fixed fangs. Once classified as a cobra (genus Naja), the king cobra was eventually moved to its own genus, Ophiophagus. The name "king cobra" is therefore a bit of a misnomer, as it's not a true cobra. Ophiophagus combines the Latin words for snake ("ophio") and eater ("phagus") — an accurate description of its habits. It is sometimes called the hamadryad, a Greek name for "wood nymph." The snake was first scientifically described by a British naturalist named Dr. Thomas Edward Cantor in 1836.

The King's Dominion

The king cobra ranges far and wide throughout tropical Asia. It's found in India, southern China, Vietnam, the Philippines, Indonesia and Malaysia, where it reaches record lengths. It prefers habitats with dense undergrowth and heavy rainfall, such as rain forests and mangrove swamps. In southern India, where herpetologist Romulus Whitaker has set up the Agumbe Rainforest Research Station and plans to establish the world's first king cobra sanctuary, it inhabits the endangered montane rain forests of the Western Ghats.

Uncanny Intelligence

The king cobra possesses a rare intelligence that scientists are only beginning to understand. Some snake experts have experienced a type of communication with the king cobra that is quite unlike any other snake species they've encountered. It has an awareness and alertness far beyond most other snakes; for instance, the male is very conscious of its territory and will chase other males away. In captivity, the king cobra is able to distinguish its caregiver from strangers, and is said to be a faster learner than other snakes. The fact that it builds a nest — the only snake to do this — is another indication of its intelligence, according to experts.

King Cobra (Ophiophagus hannah)

Lovestruck Snakes

Late in the dry season (January through March), the normally solitary king cobra goes looking for love. Shedding skin at the beginning of the breeding season causes the female to release pheromones, which helps the male track her down in the thick underbrush. The male rubs his head on the female's body to announce his intentions. If she doesn't seem interested, the Casanova will butt and push her until she agrees to mate. If another male is on the scene, the cobras will wrestle, attempting to push their opponent's head to the ground. When the female is agreeable, the male will wrap his body around her, and the two will remain in this position for several hours. It is thought that male king cobras mate with the same female in successive seasons. The female can store the male's sperm for several years until she's ready to have offspring.

A Protective Parent

In April, May or June, the female king cobra lays a clutch of 20 to 50 eggs in a nest made of twigs, leaves and other vegetation, which she scrapes together into a pile with her coils. No other species of snake does this. The heat created by the rotting vegetation helps incubate the eggs. Once the eggs are deposited, the mother hollows out a second chamber for herself. There she sits for two to three months, guarding the eggs against monitor lizards and mongooses, which may eat them; elephants, which may trample them; wild boars, which may do both; and other predacious or "clumsy" animals. If necessary she will fiercely defend her clutch, but if sufficiently disturbed may abandon the eggs early.

King Cobra (Ophiophagus hannah)

Princes and Princesses

After a 60- to 90-day incubation period, the king cobra's eggs are ready to hatch. Just before they do, the mother departs; she's fasted for two to three months and might otherwise be tempted to eat her young, as king cobras feed almost exclusively on snakes. At birth, a king cobra hatchling is around 14 inches in length and 1/2 inch wide. It's glossy black with bright yellow bands, and its venom is as potent as an adult's. Even at birth the king cobra is very alert and will flare its hood if provoked. Ten days after birth, the hatchlings molt and are ready to begin hunting. They are vulnerable to civets, mongooses, giant centipedes and army ants for the first several months.

The Cannibalistic Cobra

The king cobra preys almost exclusively on snakes, and will even cannibalize smaller individuals of its own species. It mainly preys on nonvenomous snakes, like small pythons and rat snakes, but will also eat cobras, kraits and other very venomous snakes. It will also eat the occasional monitor lizard, which is very close to snakes evolutionarily. In captivity, the king cobra can be "taught" to eat warm-blooded prey by making the animal — often a mouse or rat — smell like a snake. A diurnal snake, the king cobra actively forages for prey during the day, using its sense of smell to locate prey and excellent eyesight to strike.

Ready to Strike

When a king cobra is under attack or about to strike at prey, it quickly coils the lower two-thirds of its body, raises the front third and spreads its narrow hood. If on the defense, it will let out a long, low hiss to warn of an impending bite. If on the attack, it will skip the hissing and strike downward at its target. Unlike many of its short-fanged relatives, which have to hold and chew their victims to inject venom, the king cobra can do so with a quick strike. If its prey flees, the king cobra will give chase in an upright position so that it's ready to deliver the fatal blow at any moment.

King Cobra (Ophiophagus hannah)

Packing Poison

Though not as potent as its relatives, the king cobra's venom is still deadly. What it lacks in potency the king cobra makes up in quantity, delivering more than a teaspoon of venom in a single strike. One dose contains enough toxin to kill an Asian elephant or between 20 and 40 humans. The venom acts quickly to destroy the victim's nervous system, shutting down both the heart and lungs in a matter of minutes. The venom contains another toxin that begins digesting the prey before it even reaches the king cobra's belly. King cobra venom is used to treat tuberculosis and cholera in India, and has been developed into two pain relievers, Cobroxin and Nyloxin, in the United States.

A Growling Moan

While most snakes hiss, the king cobra lets out a growling moan. This lets intruders or potential predators know that the snake is perturbed and ready to strike. To make the sound, the king cobra fills its lungs with air, then quickly constricts its body. This forces the air through the glottis, the space between the vocal cords, resulting in a long moan, which some say resembles a dog's growl. A special resonating chamber in the snake's tracheal lung may give the sound its characteristic low pitch, which is unique among snakes. (The tracheal lung is an enlarged throat that wraps around the windpipe, allowing the king cobra to breathe while it's swallowing prey.)

King Cobra (Ophiophagus hannah)

King Cobra Culture

The king cobra is revered as a deity in many parts of India and southeast Asia. Some believe that it controls the rain, thunder and fertility. In one Indian snake cult, a large king cobra is brought to the village in a basket. When the lid is open, the snake rises up and a priestess kisses it on the head, guaranteeing both human and crop fertility. Some believe that if this secretive snake is seen by 100 people, it will die. So, in accordance with this belief, the king cobra will enter a village when it's ready to pass on to the next life.

A Vanishing Species

Though widespread, the king cobra is uncommon in every part of its range and is considered rare in India. Habitat loss is a major threat to its survival. Forests are disappearing at an alarming rate in many parts of its range, driving the shy snake into populated areas where it's often killed out of fear. The king cobra is also harvested for commercial purposes. Its meat, skin and bile are used in traditional Chinese medicines, and its venom is used to treat pain and illness. The Whitley Fund for Nature is a U.K. registered charity involved in king cobra conservation. They support the work of herpetologist Romulus Whitaker, who has gone to great lengths to save the king cobra and its rainforest habitat in southern India.