The king cobra, or Ophiophagus hannah, is the world's longest poisonous land snake. Its length averages 12-13 feet (3.6-4 m), although individual snakes have been found that are as long as 18.5 feet (about 5.7 m). King cobras are slender snakes and typically do not weigh more than 45 pounds (about 20 kg). The male king cobra is longer and weighs more than the female, which is unusual in snakes. This snake will live about 20 years in the wild.
King cobras vary in color, depending on where they live. These snakes might be black, brown, green, tan or yellow and have either white or yellow bands around their bodies. The color of their bellies ranges from a solid cream to an off-white shade with dark bars. Scientists have noted that king cobras living in dark forests tend to be a darker color than those living in grasslands or more open woodlands. Its most distinctive physical feature is the hood on its head, which flares when cervical ribs along its neck are extended and cause loose skin to spread.
Geographically, the king cobra is found throughout much of Southeast Asia. It also is found in the Philippines, Indonesia and Malaysia as well as in India and the southern part of China. Although it lives on land, the king cobra is a good swimmer, and it likes to be in areas with streams and lakes. King cobras are at home in woodlands, bamboo thickets, grasslands, swamps and rain forests. In more mountainous regions, they might be encountered at altitudes as high as 6,500 feet (1,981 m).
The king cobra is carnivorous, with the majority of its diet being other snakes, such as the Asian rat snake, which is its favorite food. It prefers snakes of the non-poisonous variety, but it will eat other poisonous snakes, such as kraits, and even other cobras, including its own species. When it has difficulty finding other snakes to eat, the king cobra will eat rodents, birds, lizards and other small vertebrates. King cobras have excellent senses of smell and sight, and they can identify prey as far away as 300 feet (100 m).
Breeding season is from about January to April. The king cobra is the only snake that constructs a nest for its eggs. Females build nests from vegetation which, as it decays, serves to warm and incubate the eggs. The female lays 20-60 eggs, then stays and guards the nest. Eggs hatch after 60-80 days, and the young snakes are immediately independent.