It’s tricky to measure a snake, especially in the wild, says Beki Hooper. Given that they are, basically, one long line, this might be a bit of a surprise, but snakes rarely cooperate with a ruler – they slither and bend, contract and relax, and seldom stay still for long enough to be measured.
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Dead snakes, it turns out, aren’t any more straightforward. While they can easily be stretched straight, their muscles are completely relaxed, meaning they consistently end up measuring longer than living snakes.
And even shed skin isn’t accurate. It stretches as it comes off a snake’s body, and can be up to twice as long as the body it came from.
So, it’s not easy to get reliable measurements of snakes, especially in the wild (captive snakes can grow much larger than their wild counterparts).
Below are the eight longest wild snake species according to reliable estimates. Included are behemoth snakes that can swallow a human whole, kill a person with a single bite, and hunt in gravity-defying teams…
Biggest snakes in the world
Amethystine python (Simalia amethistina)
18-feet (5.5-metres)
Found in the rainforests of Indonesia and Papua New Guinea, this tree-dwelling python can grow up to 18-feet (5.5-metres) long. They can slither up trees astoundingly well, using their powerful muscles to spiral up trunks.
As with all pythons, they are not venomous, and kill their prey by ambushing them then wrapping their muscular bodies around their body, squeezing tighter and tighter every time their victim breathes out.
For a long time, it was thought python prey died through suffocation, but it turns out that python victims usually die from heart attacks while they are being squeezed.
Smaller amethystine pythons eat modestly sized prey such as birds, bats, rats and possums, but the biggest individuals can swallow animals as large as wallabies.
Like crocs, these snakes will often ambush their victims while they are seeking a drink. With its head lowered to the water, prey is much easier to sneak up on, and these snakes are as skilled in the water as they are in the trees.
7: Australian scrub python (Simalia kinghorni)
18.5-feet (5.7-metres)
A close relative of the amethystine python, the Australian scrub python lives in northern Australia and can grow up to 18.5-feet (5.65-metres). It is the longest snake in Australia, and is the country’s biggest terrestrial predator (not the dingo, as many think).
As with its close cousin, the amethystine python, the Australian scrub python can eat pretty big prey. Golfers in Queensland had quite the sight when their games were interrupted by a scrub python swallowing up a wallaby on the golf course.
In another sighting, Queensland police stumbled across a large individual slithering across a road.
It’s not super rare for these gigantic snakes to find their way into people’s houses and cause a ruckus in the rooms they slither through. Thankfully, there are no reports of either the Australian scrub python or the amethystine python ever eating a person (although some have, apparently, tried).
6: Cuban boa (Chilabothrus angulifer)
18.5-feet (5.7-metres)
Coming in equal with the Australian scrub python at a maximum of 18.5-feet is the Cuban boa. This boa species is native to Cuba and surrounding small islands.
Boas are much like pythons. They are nonvenomous, and kill by ambushing and then squeezing their prey to death.
Cuban boas are constrictors with a difference, though. While most snakes live and hunt on their own, Cuban boas work together to catch their prey.
In the dark caves of Cuba, these boas hang upside-down from the cave ceiling. Amazingly, they hang in formation, and together they form a fence.
These fences mean that fruit bats – who must leave the cave to feed – have little chance of avoiding a snake. Once they are caught in a snake’s jaws, there is no escape: they are crushed and swallowed whole.
By forming these fences along cave ceilings, each snake increases its own chance of a meal.
This is the only land-based species of snake known to hunt cooperatively. I, for one, am very glad not to be a fruit bat in a Cuban cave…
5. King cobra (Ophiophagus hannah)
18.7-feet (5.7-metres)\
The only venomous snake to make the top eight, the king cobra is perhaps the most famous of the lot. Living in tropical and subtropical Asia, the longest individual ever reliably measured in the wild was (as with the Cuban boa and Australian scrub python) 18.7-feet (5.7-metres) long.
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This individual, caught in Malaysia in 1937, was brought into captivity and housed at London Zoo. Sadly, at the outbreak of World War II, it was decided that the snake should be euthanised in case the zoo was bombed and the snake escaped – this scenario was deemed too high a risk to the public.
King cobras have incredibly potent venom, and one bite has enough venom to kill twenty humans.
They use their venom to immobilise prey before swallowing it whole. A neurotoxin, the venom causes paralysis to creep from the site of the bite to the rest of the body, eventually resulting in collapse of the respiratory system and then death.
Fortunately, king cobras rarely bite humans. These snakes are shy and avoid humans as much as possible. Bites usually occur when the snake is either defending itself or its nest.
Which leads to the final fact about this snake: they are the only snake species to build nests of leaf litter. These nests look quite cosy to curl up in – if you are a King cobra, that is. The presence of a very protective, extremely venomous mother is enough to put anyone else off curling up inside.
4: Burmese python (Python bivittatus)
19-feet (5.8-metres)
Native to southern and southeast Asia, these monster snakes have also established an invasive population in North America – most notably in Florida. Growing up to 19-feet (5.8-metres), these are the fourth longest snakes in the world.
Burmese pythons have been known to swallow crocs and alligators whole, although they do occasionally overestimate what they can handle. In 2005, a Burmese python tried to eat an alligator that was just a little too much for it. Both were found dead after the snake burst open.
Burmese pythons can go a whopping year and a half without a meal, and when they do eat, their hearts can increase in volume by 40%. This extra circulatory power helps with digestion – a mammoth physiological task when digesting something as big as a croc.
These pythons have recently been found to have special bone-digesting cells in their intestinal linings. These cells help the snakes digest their entire prey – bones and all – without getting poisoned by too much calcium. Many other snake species are likely to have these cells, too.
3: Green anaconda
20.7-feet (6.3-metres)
Recently found to be two species – the northern green anaconda (Eunectes akayima) and the green anaconda (Eunectes murinus) – these boas are native to South America and the Caribbean. They are often found in the deepest, most remote parts of the rainforest, and are as at home in water as they are on land.
The longest reliably recorded individual was almost 21-feet (6.3-metres), although rumours of absolute monsters have long circulated. When zoologist Alfred Russel Wallace went to the Amazon in the 1800s, he heard stories of 40-foot (12-metre) anacondas.
Green anacondas eat prey as large as tapirs, and can even eat jaguars. While there are many stories about anacondas eating humans, there are no documented cases.
A rather peculiar quirk of green anacondas is their mating behaviour. More than ten males can form a ‘breeding ball’ around a female, where they wrestle for prime mating position for up to a month.
2: African rock python
21-feet (6.5-metres)
The Central African rock python (Python sebae) and Southern African rock python (Python natalensis) both live in sub-Saharan Africa. They can grow to 21-feet (6.5-metres).
Much like the Burmese python, large individuals can swallow incredibly big prey – we’re talking crocodiles and antelope, and even the cubs of big cats such as leopards and lions.
In 2017, a rock python was filmed swallowing an adult hyena, estimated to be about 70kgs (the same weight as a human).
Greatly feared in their native range, rock pythons don’t often pose a threat to humans. But sometimes, they can be deadly. In 2002, a 10-year-old child was reportedly swallowed by a rock python in South Africa.
Unlike many other snakes, and unlike pythons in particular, rock python mothers protect their young once they have hatched. The mother will stay with her hatchlings for a few weeks to make sure they get a good start in life, showing a more tender side to these hyena-hunting mega-snakes.
1: Reticulated python (Python reticulatus)
22.8-feet (7-metres)
Coming in at number one is south and southeast Asia’s giant: the reticulated python.
While most mega-snakes are not man-eaters, this species can and do swallow humans – children and adults alike – whole.
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An anthropologist who lived with a tribe in the Philippines reported that one in four of the tribe’s men had been attacked by reticulated pythons. Most were able to fight the snakes off, but some were not so lucky.
Recently, an Indonesian woman was eaten by a reticulated python when she went to check on her vegetable garden.
Humans are not usually on the menu for these pythons, though. Most eat rats and other small animals, but bigger individuals need more calories and therefore wait for bigger prey. These bigger specimens most often eat large animals such as pigs and even cattle.
While a 22.8-foot individual is the longest reliably recorded reticulated python, there have been reports of individuals reaching almost 33-feet (10-metres) long. That’s the length of a double decker bus!
