Snakes can grow to enormous sizes, although some reports have long been exaggerated. The largest snakes belong to the python and boa family. Which family contains the largest depends on whether you are measuring these reptiles by weight or length. While man-eating snakes are extremely rare (although they are known to occur), there are still some truly enormous reptile species crawling on our planet.

1. What is the longest snake in the world?

The reticulated python (Malayopython reticulatus) is the longest snake in the world, typically exceeding 6.25 meters in length. It is the longest of the 39 species in the python family.

The longest reticulated python on record was discovered in 1912, measuring an astonishing 10 meters in length, more than half the length of a bowling alley, making this snake longer than a giraffe. Reticulated pythons live in Southeast Asia, and while they are typically found in rainforests, woodlands, and grasslands, their habitat preferences appear to depend on their location. In Myanmar, these non-venomous snakes have been found only in primary forests, while they have also been found in sewers in Singapore, Indonesia, and Borneo, Malaysia.

Reticulated pythons are about 60 centimeters long when they hatch, but they can grow to a huge size during their lifetime.

As is well known, reticulated pythons climb trees by tightly wrapping their bodies around tree trunks and using their muscles to lift themselves upwards. The longest and heaviest captive snake ever recorded was a female reticulated python named Medusa. Held in the United States, Medusa measured 7.67 meters long and weighed 158.8 kilograms. Green anacondas (Eunectes murinus) are also exceptionally long snakes. However, exaggerated length measurements have been made in the past, with snakes reportedly exceeding 24 meters in length. In reality, green anacondas rarely exceed 6.25 meters.

2. The longest venomous snake

The king cobra is the world's longest venomous snake. This one displays its length in a raised, defensive posture.

The king cobra (Ophiophagus Hannah) is the world's longest venomous snake. In 1937, a 5.54-meter-long king cobra was discovered in Negeri Sembilan, Malay Peninsula. It was captured and kept at the London Zoo, eventually growing to 5.71 meters. However, this enormous snake was killed at the outbreak of World War II to prevent public danger should the zoo be bombed and the snake escape.

For king cobras, exceeding 5 meters is uncommon, although their average length is 3.7–4.6 meters, making them large animals. These snakes best display their length when they feel defensive or need to see high grass or bushes. They will raise the front of their body to about one meter off the ground, and can even chase threats in this posture. As an additional intimidation strategy, they hiss and flatten their neck ribs into a hood, forming the classic cobra shape.

A museum worker holds a king cobra specimen from the 1930s. It is believed that the specimen may have just arrived at the museum when this photo was taken.

However, these snakes generally prefer to flee rather than fight. King cobras are found in a variety of habitats in South and Southeast Asia, including forests, mangrove swamps, and some farmland with woodland remnants. They are also excellent swimmers.

However, they are generally uncommon in any of their habitats except for some forested areas in Thailand. King cobras are listed as vulnerable by the International Union for Conservation of Nature (IUCN). Due to habitat loss and exploitation (such as harvesting for skin, food, and medicinal purposes), parts of their distribution range face a population decline of over 80% within 10 years.

3. The longest sea snake

The yellow sea snake is considered the longest sea snake species in the world.

The yellow sea snake (Hydrophisspiralis) can reach a length of 2.75 meters, making it the longest sea snake species. However, most collected specimens are less than two meters long. The yellow sea snake inhabits the northern Indian Ocean and parts of Southeast Asia, and can also be found near New Caledonia in the southwestern Pacific.

All sea snakes, including the yellow sea snake, have paddle-like tails that help them move in the water. This is the tail of the yellow-bellied sea snake.

Little is known about these sea snakes. Records indicate that the species lives up to 50 meters below the surface, typically on muddy, sandy bottoms, and feeds on eels.

4. What is the heaviest snake in the world?

The green anaconda is the heaviest snake in the world. However, their size has been exaggerated in the past.

The green anaconda is the heaviest snake in the world. The heaviest anaconda on record weighed 227 kilograms. This giant snake was 8.43 meters long and had a circumference of 1.11 meters. Although the reticulated python is longer, it is also quite slender. Pythons are enormous. It is estimated that a 5.2-meter-long anaconda weighs about the same as a 7.3-meter-long reticulated python.

Anacondas spend most of their time in the water, with their eyes and nostrils located on the top of their heads.

Green anacondas are non-venomous, solitary creatures found in South America and Trinidad. They spend most of their time in the water, typically in swamps, marshes, slow-moving streams, and rivers. Because of this, their nostrils and eyes have evolved to be on the top of their heads, rather than on the sides, allowing them to breathe and see prey and predators on the surface while their massive bodies remain submerged.

These snakes have a diverse diet, ranging from turtles and fish to peccaries, deer, capybaras (the world's largest rodents), and even, in rare cases, jaguars. Anacondas belong to the python family and use their long, muscular bodies to constrict their prey.

In 1912, a large python was removed from its crate upon arrival at the New York Zoo (now the Bronx Zoo). Image: Internet Archive Book Image from Flickr

Although "anaconda" usually refers to the green anaconda, there are actually three other smaller anaconda species: the Bolivian anaconda (Eunectes beniensis), the black-spotted anaconda (Eunectes deschauenseei), and the yellow anaconda (Eunectes notaeus). They are all found in South America.

5. The most venomous snake

The Eastern Diamondback Rattlesnake is the heaviest venomous snake in the world.

The Eastern Diamondback Rattlesnake (Crotalus adamanteus) is a rattlesnake considered the heaviest venomous snake in the world, with a massive size, reaching up to 2.56 meters in length and weighing up to 15 kilograms. However, the Eastern Diamondback Rattlesnake typically weighs 5.5-6.8 kilograms and is 1.5-1.8 meters long.

This snake is found in the southeastern United States and prefers flat woodland, coastal forest, and scrubland habitats. Although it is a confident swimmer and can occasionally be seen between swamps and barrier reefs, it is not common in wet areas.

Rattlesnakes get their name from the rattling sound produced at the end of their tails. This structure consists of interlocking hollow segments. These snakes vibrate their tails rapidly, producing a rattling sound to warn potential predators.

Adult eastern rattlesnakes feed on small mammals such as rabbits, squirrels, and small birds, while juveniles feed on mice. They attack their prey with a venomous bite, then let it crawl away and die, at which point the snake eats it.

The Gaboon snake (Bitis gabonica) is another large snake, but it is not as heavy as the Eastern Diamondback Rattlesnake. However, an exceptionally long individual, reaching 1.83 meters in length, weighed 11.34 kilograms.

The Gaboon snake has the longest fangs among snakes.

Although the Gaboon viper is generally not as heavy as the Eastern diamondback viper, it has the longest fangs of all snakes, reaching up to 55 millimeters. Its venom yield is also the highest, capable of carrying up to 600 milligrams at a time.