Discover the Largest Venomous Snake Ever: 3X Bigger than a King Cobra!

Closeup of Jamaican boa
© reptiles4all/

Written by Emmanuel Kingsley

Updated: August 29, 2023

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You probably know that the king cobra is the largest venomous snake known to humans, but what if this isn’t entirely true? It all began in 1857 when British paleontologist Richard Owen discovered 13 fossils that led him to publish his findings of a new species of viper, which he claimed to be the largest ever!

However, Owen’s findings got lost in time until 157 years later! A single fossil was rediscovered near Thessaloniki, northern Greece, giving credibility to Richard Owen’s discovery many years before. Discover the largest venomous snake ever. A tip – it’s three times bigger than a king cobra.

"Largest" infographic for the largest venomous snake ever, the extinct Laophis crotaloides.
Although Owen’s findings were forgotten for many years, another fossil discovery has renewed research.

What is the Largest Venomous Snake Ever?

In 1857, Richard Owen, who had derived the word “dinosaur,” described an unbelievable finding. Owen claimed to have found 13 fossil vertebrae of an enormous snake near Thessaloniki, Greece. He named the species Laophis crotaloides.

From its fossils, Owen was not only able to determine the snake’s size and weight but also its snake family. He stated that the Laophis crotaloides was a viper that weighed 57 pounds and measured between 10 and 13 feet in length.

King cobras, which are currently recognized as the largest venomous snake species can grow up to 18 feet but hardly exceed 20 pounds in weight. Consequently, it is safe to say that king cobras are close to only a third of Laophis crotaloides’ weight.

Laophis crotaloides lived in Greece (and perhaps other parts of the world) about 4 million years ago. This means that they inhabited areas with grasslands, thick vegetation, and cold weather. Because most snakes today hibernate through winter and come out only when the weather is warm, it is astounding how Laophis crotaloides survived and grew to such size.

laophis crotaloides

Fossil evidence revealed the largest venomous viper, Laophis crotaloides, first discovered in 1857.

©Richard Owen / public domain – Original

Where Did They Live?

Laois crotaloides is an extinct species of snake that lived in Greece (and possibly other parts of the world) around 4 million years ago. The remains of Laois crotaloides were first discovered in Greece in 1857, and since then there has been further research into its existence and range. Today, it is believed that Laois crotaloides may have also lived outside of Greece during this time period but due to lack of evidence, this still remains uncertain.

Laophis Crotaloides Venom

Not much is known about Laophis crotaloides and sadly, the single fossil discovered cannot tell us enough to figure out the monster’s venom type. However, we do know that it is a viper and safely assume that it had venom similar to many vipers today.

Generally, vipers have venom composed of enzymatic and nonenzymatic proteins. Usually, their venom attacks tissues and causes death- if the venom is strong enough and left untreated. It also causes necrosis and coagulopathy- not to mention the intense pain and swelling that accompany viper bites. They also have long hollow solenoglyphous fangs that allow them to inject their venom like one would use a hypodermic needle.

Laophis Crotaloides Diet


Laophis crotaloides probably fed on small mammals.

©Save nature and wildlife/

Georgios Georgalis, a researcher, believes that these snakes fed very similarly to snakes today. Even though the snake lived among some really large animals, he believes it fed on a diet of small mammals such as rodents. Georgalis presented his findings on the Laophis crotaloides to the Society of Vertebrate Paleontology in Berlin on the 6th of November, 2014.

Laophis Crotaloides vs Other Snake Species

Without a doubt, the Laophis crotaloides is one of the largest venomous snakes ever discovered. You already know how it compares to the king cobra in size. But how does it compare to other snake species?  Let’s take a look at 8 large snake species compared to the Laophis crotaloides.

Laophis Crotaloides vs Largest Garter Snake Ever Recorded

garter snake slithering on rocks

Laophis crotaloides were longer than garter snakes.


Garter snakes are harmless snakes. They have venom that is only dangerous to their prey. These snakes are usually medium-sized, measuring between 23 and 30 inches. The largest garter snake ever discovered measured 52.8 inches (4.4 feet). This makes them tiny compared to Laophis crotaloides.

Generally, garter snakes have easy-going temperaments and are often kept as pets, unlike venomous pit vipers. You can identify these snakes by their varying colors and patterns. They are some of the most beautiful snakes known to man.

Laophis Crotaloides vs Largest Tiger Rattlesnake Ever Discovered

Tiger rattlesnake with large rattle

Laophis crotaloides were longer than



©Vladislav T. Jirousek/

Tiger rattlesnakes are named for their tiger-like patterns. They are known to be one of the deadliest snakes in Northern America. Tiger rattlesnakes inject only about 11 mg of dried venom in each bite. This is much lower than other snakes.

However, it is still life-threatening and capable of killing a person. Despite this, it is still incredibly potent and life-threatening. On average, these snakes measure 24 inches. However, the largest specimen of tiger rattlesnake discovered measured 35.9 inches (3 feet).

Laophis Crotaloides vs Largest Hognose Snake Ever Discovered

hognose snake curled up in grass

Laophis crotaloides were longer than hognose snakes.


Hognose snakes are popular for their weird noses and their dramatic attitudes. They are usually sand-brown markings of varying colors. These snakes are nonvenomous and measure 2 to 4 feet on average. They are known to attain a maximum length of 6 feet.

Laophis Crotaloides vs Largest Anaconda Ever Discovered

Green anaconda

Anacondas were longer and heavier than Laophis crotaloides.


Anacondas are known for their sizes and length. Consequently, there are several reports that claim to have discovered the largest specimen. However, the largest and most verifiable claim points to a 27.7-foot-long anaconda that weighed over 500 pounds.

Laophis Crotaloides vs Largest Blood Python Ever Discovered

Red Blood Python / Python curtus brongersmai

On average, blood pythons weigh 4-6 pounds, but the largest on record weighed over 50 pounds and measured 10 feet long.

©dwi putra stock/

Blood pythons are nonvenomous snakes found in various parts of the world. On average, they weigh 4 to 6 pounds. However, the largest blood python ever discovered weighed over 50 pounds and measured about 10 feet.

Laophis Crotaloides vs Largest Eastern Diamondback Rattlesnake Ever Discovered

Large eastern diamondback rattlesnake

The Laophis crotaloides is one of the largest venomous snakes ever discovered.

©Chase D’animulls/

According to the Guinness Book of World Records, a man, identified by only the singular name Rutledge holds the record for the largest eastern diamondback rattlesnake. The snake was caught in 1946 and measured 7 feet, 8 inches while weighing 34 pounds. On average, eastern diamondbacks weigh 4 to 5 pounds and measure 4 to 5 feet.

Laophis Crotaloides vs Largest Western Diamondback Rattlesnake Ever Discovered

Western Diamondback Rattlesnake (Crotalus atrox)

Laophis Crotaloides are longer than western diamondback rattlesnakes.

©Alexander Wong/

Western diamondback rattlesnakes are some of the most venomous species known to man. They are usually colored with mixtures of brown, yellow, brick red, or yellowish/pinkish-white. On average, these animals measure 4 feet but may reach 5 feet. The largest western diamondback rattlesnake ever discovered was 7 feet and 8 inches in length.

Laophis Crotaloides vs Largest Burmese Python Ever Discovered

Burmese Python hanging in a tree, waiting for prey.


pythons grow to record-breaking sizes.

©Heiko Kiera/

The largest Burmese python ever discovered was found in the Everglades, Florida. It measured 18 feet, 9 inches, and weighed 104 pounds! It was captured by the Florida Fish and Wildlife Commission.

Other Record-Breaking Snakes

Baird’s rat snakes are a type of serpent that can be found in North America. They are medium-sized snakes, usually growing to lengths of between 2 and 5 feet, making them relatively small in comparison to other snake species.

These snakes are not known for being the largest in their family, but they can still reach impressive sizes, with some individuals measuring up to 25 to 55 inches (64 to 140 cm) in total body length (including tail).

It is important to note that the largest Baird’s rat snake ever recorded has not been officially documented, so there is no exact data on its size. Hatchlings of Baird’s rat snakes, on the other hand, usually measure 11.8 inches (30 cm) in length on average. In terms of weight, rat snakes are relatively light, with an average weight range of 1.3-4.8 lb (0.6-2.2 kg).

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