The King cobra is the world's longest venomous snake. They are dark olive or brown in color with black bands and white or yellow crossbands. Their head is black with two crossbars near the snout and two behind the eyes. The belly is cream or pale yellow. Juveniles are shiny black with narrow yellow bands. The head of a mature snake can be quite massive and bulky in appearance, though like all snakes, it can expand its jaws to swallow large prey items. The King cobra is a highly venomous and dangerous snake when agitated or provoked that has a fearsome reputation in its range, although it is typically shy and avoids confrontation with humans when possible. This snake is a prominent symbol in the mythology and folk traditions of India, Sri Lanka and Myanmar. It is the national reptile of India.
King cobras are distributed across the Indian subcontinent, Southeast Asia, and the southern areas of East Asia, in Bangladesh, Bhutan, Brunei, Cambodia, China, Hong Kong, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, the Philippines, Singapore, Thailand, Vietnam, and southern China. In India they occur from Goa; Western Ghats of Karnataka, Kerala and Tamil Nadu; the east coastline of Andhra Pradesh and Odisha; Sundarban mangroves; Himalayan foothills from Uttarakhand, Uttar Pradesh, Bihar, northern parts of West Bengal to most of the north-east region and the Andaman Islands. These snakes live in dense highland forests, bamboo thickets, mangrove swamps, and even agricultural areas. They prefer areas dotted with lakes and streams and may also swim in rivers.
King cobras are solitary creatures and only come together to mate. They are active throughout the day, but may also be seen at night. King cobras, like other snakes, receive chemical information via their forked tongue, which picks up scent particles and transfers them to a special sensory receptor (Jacobson's organ) located in the roof of their mouth. When the scent of a meal is detected, the snake flicks its tongue to gauge the prey's location (the twin forks of the tongue acting in stereo); it also uses its keen eyesight. King cobras are able to detect moving prey almost 100 m (330 ft) away. Their intelligence and sensitivity to earth-borne vibration are also used to track their prey. When annoyed, King cobras prefer to escape and avoid confrontation. However, if continuously provoked, they can be highly aggressive. When alarmed, they rear up the anterior portion (usually one-third) of their body when extending the neck, showing the fangs and hissing loudly. When raising their body, King cobras can still move forward to strike with a long-distance and people may misjudge the safe zone. This snake can deliver multiple bites in a single attack, and adults are known to bite and hold on. If King cobras face a natural predator, such as the mongoose, which has resistance to the neurotoxins, these snakes generally try to flee. If unable to do so, they form the distinctive cobra hood and emit a hiss, sometimes with feigned closed-mouth strikes.
King cobras are carnivores and their diet consists primarily of other snakes and even other venomous snakes such as various members of the true cobras and the krait. When food is scarce, King cobras also feed on other small vertebrates, such as lizards, birds, and rodents.
King cobras are suggested to be monogamous returning to a previous mate every breeding season. They breed from January through April. King cobras are oviparous (egg-laying). Females build a nest in which they lay 12 to 51 eggs and guard it during the incubation period of about 51 to 79 days. The hatchlings are 31 to 73 cm (12 to 29 in) long and weigh 18.4 to 40 g (0.65 to 1.41 oz). They are independent at birth. The King cobra is unusual among snakes in that the female is a very dedicated parent. For the nest, the female scrapes up leaves and other debris into a mound and stays in the nest until the young hatch. She guards the mound tenaciously, rearing up into a threat display if any large animal gets too close. Inside the mound, the eggs are incubated at a steady 28 °C (82 °F). When the eggs start to hatch, the female leaves the nest. The baby King cobra's venom is as potent as that of the adults. They may be brightly marked, but these colors often fade as they mature. They are alert and nervous, being highly aggressive if disturbed.
King cobra populations have dropped in some areas of its range because of the destruction of forests and ongoing collection for the international pet trade. These snakes also suffer from harvesting for meat, skin, and use in traditional medicine.
The IUCN Red List and other sources don’t provide the number of the King cobra total population size. Currently, this species is classified as Vulnerable (VU) on the IUCN Red List and its numbers today are decreasing.