The king cobra (Ophiophagus hannah) is an elapid found predominantly in forests from India through Southeast Asia. This species is the world's longest venomous snake, with a length up to 18.5 to 18.8 ft (5.6 to 5.7 m). Despite the word "cobra" in its common name, this snake is not a member of the Naja genus ("true cobras"), which contains most cobra species, but the sole member of its own genus. It preys chiefly on other snakes and occasionally on some other vertebrates, such as lizards and rodents. The king cobra is a dangerous snake that has a fearsome reputation in its range, although it typically avoids confrontation with humans when possible.

The longest known specimen was kept captive at the London Zoo, and grew to around 18.5 to 18.8 ft (5.6 to 5.7 m) before being euthanised upon the outbreak of World War II. The heaviest wild specimen was caught at Royal Island Club in Singapore in 1951, which weighed 12 kg (26 lb) and measured 4.8 m (15.7 ft), though an even heavier captive specimen was kept at New York Zoological Park and was measured as 12.7 kg (28 lb) at 4.4 m (14.4 ft) long in 1972.

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