The Longest King Cobra Was As Long as a Killer Whale -3 Reasons It Grew So Large

Written by Kyle Glatz
Updated: September 4, 2023
© mrjo/
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King cobras are impressive snakes. They have incredibly powerful venom, hunt other large snakes for food, and are among the smartest snakes alive today! King cobras are also the largest venomous snakes in the world. In fact, the longest king cobra was as long as a killer whale. Discover how long this snake grew as well as three reasons why it got so long throughout its life!

"Largest" infographic for the longest King Cobra Ever
King Cobras are the largest venomous snake in the world, but their average length is 11-13 feet.

The longest king cobra ever was 18 feet 4 inches long when it was caught and about 18 feet 8 inches at its greatest length! That is a massive snake compared to the average king cobra that grows about 11 to 13 feet long. The largest king cobra was captured in Negeri Sembilan, Malaysia in 1937. The snake was transported from that country to the London Zoo where it was put on display.

Many people know that king cobras can lift about a third of their body off the ground. This defensive posture gets them ready to lunge at enemies. The longest king cobra ever probably could have pulled enough of its body off the ground to look most people in the eye!  That would allow them to deliver venom to all the most sensitive places on a human’s body.

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The monstrous king cobra continued to grow in the zoo. Unfortunately, the outbreak of World War II brought some challenges to the London Zoo. With the threat of war literally looming overhead, the zoo decided the best course of action would be to cull their venomous snake population.

Otherwise, if a bomb struck the right spot, venomous snakes could be unleashed into the city. So, the largest king cobra ever known was sort of a casualty of war.

How Big is a Killer Whale?

An average female orca is about the same length as the longest king cobra.


Now, the original comparison in our title said that the longest king cobra was the size of a killer whale. The average killer whale, or orca, is about 16 to 23 feet for a female and 20 to 26 feet for a male. So, the longest king cobra ever recorded could be longer than an average female. Of course, the snake could only match the killer whale in terms of overall length, not weight. While king cobras are very long snakes, they only weigh about 13 pounds on average.  

3 Reasons Why the King Cobra Grew So Large

King cobra
King cobras grow large when they have food, protection, and good genes.

©Eric Isselee/

Snakes can achieve great lengths throughout their lives in the right conditions. For example, the longest king cobra probably got so long due to its lifespan, diet, and genetics. Let’s take a closer look at each of these elements to see how these factors affected its growth.

1. The Snake Lived a Long Time

The first reason that the king cobra got so long was that it lived a long time. The average king cobra will mature by the time it becomes 5 or 6 years old. However, they will continue to grow each year. The average king cobra sheds about four or five times every year, slowly growing. The largest king cobra was still growing from the time it was captured until it died.

Originally, the snake was 18 feet 4 inches. In the two years after it was captured, the snake grew another four inches. The snake probably lived a long time to achieve that length.  

2. The Snake Had Plentiful Food Sources

Another thing that would have helped the king cobra achieve a great length is access to good food sources. In the wild, king cobras consume many foods, including other snakes. For the snake to continue growing throughout its life, it had to have access to good nutrition. Malaysia has a wide assortment of snakes throughout the area. Hypothetically, the king cobra had a veritable buffet available.

The snake may have had a more diverse diet than other members of its species. Some snakes become specialized with their meal preferences, only consuming a certain kind of snake. That was probably not the case with this specimen.

3. The King Cobra Got Larger Than Normal from Good Genetics

Some king cobras have a long life and access to food but still never reach 18 feet 8 inches in length. That means the king cobra had to have some great genes. Instead of stopping at the average length, the king cobra kept breaking record after record. This outlier snake could have kept growing if the zookeepers were not forced to euthanize it. We’ll never know how much longer the snake could have gotten.

The snake’s age, diet, and genetics all played a role in making it the longest to ever exist. For all we know, that could be the longest one the world ever sees. King cobras are losing territory and are frequently killed out of fear.

What Snakes Are Longer Than King Cobras?

reticulated python
The reticulated python can grow to 30 feet long!


Although king cobras are very lengthy snakes, they’re not the longest in the world. Several snake species measure over 20 feet long at their biggest. For example, records of reticulated pythons, Burmese pythons, and green anacondas show that these reptiles reached far greater than the king cobra’s 18.8 feet.

Moreover, the longest king cobra was an anomaly at its greatest length, and few others have come close. Yet, scientists and wildlife experts have recorded many pythons and anacondas over 20 feet in the last century.

While the longest king cobra was as long as a killer whale, it was not as long as a big killer whale. Still, the fact that the king cobra reached about 150% of the average length of its species is amazing. We’ll never know just how long the snake could have grown if it was allowed to live. However, we can guess that diet, lifespan, and genetics all played a role in letting it reach its utmost size.

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About the Author

I've been a freelance writer since 2013, and I've written in a variety of niches such as managed service providers, animals, and retail distribution. I graduated from Rowan University in 2014. When I'm not working, I enjoy playing video games, reading, and writing for fun.

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