Discover the Largest Rattlesnake Ever!

Written by AZ Animals Staff
Published: September 5, 2021
Written by AZ Animals Staff
Published: September 5, 2021


The longest species of venomous snake in North America is the Eastern Diamondback Rattlesnake , or Crotalus adamanteus. They are also the longest Rattlesnakes in the world, so it should come as no real surprise that the largest rattlesnake ever found was also an Eastern Diamondback.

In 1946, an eastern diamondback specimen was shot by a hunter, identified by only the singular name Rutledge in the 1982 Guinness Book of World Records, and it measured seven feet nine inches in length. His kill weighed 34 lbs, which is about as much as four gallons of milk. That is definitely heavy for a Rattlesnake , but it is not as heavy as several other shorter species of venomous snake, such as the Gaboon Viper. There is no mention of where the animal was killed or how old it was when it was shot.

While it is purported that these snakes can reach lengths of up to eight feet, no snake matching that size, when appropriately measured from nose to the base of the rattle, has ever been located. Two Eastern Diamondback specimens which were supposedly longer than Rutledge’s were killed in Florida . However, their reported lengths, both in excess of eight feet, have been called into question because it is suspected the snakes were actually measured to the tip of the rattle instead of merely to the base, as is the standard. The Guinness Book does not give any information on when they were killed or by whom.

No other eastern diamondback rattlers of that length have ever been documented since that time. In the 1950s a man named E. Ross Allen reportedly offered a reward for a live Rattlesnake specimen that was at least eight feet long, but he stated no one ever claimed the reward. He did receive skins that exceeded that length, but the length of a skin is not an accurate indication of how long the snake was while alive.

Largest Rattlesnake
Western Rattlesnake coiled with rattle erect and forked tongue extended.

How Large Is 7 ft. 9 in for a Rattlesnake?

Though finding a seven foot Rattlesnake is hardly unheard of, most Rattlesnakes are under six feet in length, usually around five and a half feet, the same size as the average human being. 34 lbs is quite heavy, however, as most Eastern Diamondback Rattlesnakes weigh in around 10-15 lbs. By comparison, the largest timber Rattlesnake ever recorded was only about six and a half feet long.

Next Largest Eastern Diamondback Rattlesnakes

In September 2009, in St. Augustine, Florida , an Eastern diamondback was caught and killed inside a subdivision by a local animal trapper. That specimen was seven feet three inches long, though photographs taken on the day by local sheriff’s deputies make it appear much larger. If its weight was recorded, it was unfortunately not reported by any news outlets.

In February of 2021, the Central Florida Zoo and Botanical Gardens, announced it had a Rattlesnake of similar size. Theirs weighs 20 lbs and is seven feet four inches long, or about the length of a queen size mattress and a medium-sized dog. Edgar, as they have named their Rattlesnake , was born in captivity and was 19 years old as of 2021. He is actually more rare for his coloration than his size. Edgar the snake is also an albino, meaning he has no pigmentation in his skin or eyes. Most Rattlesnakes do not live past 20 years old, so Edgar is an elderly specimen.

Largest Rattlesnake
An Albino Western Diamondback Rattlesnake. The rattle of the rattlesnake is made up of a protein called keratin (the same protein that your hair and fingernails are made of). A new segment is added each time a rattlesnake sheds.

Largest Rattlesnake Controversy

While there is no question that the Eastern Diamondback which was found in Florida is one of the largest Rattlesnakes on record, during the late fall of 2009, posts about the snake began circulating around the internet. These posts contained the actual photographs of the snake, but the information about the snake’s size and location had been falsified to reflect a length more than twice that of the snake that was actually found. As previously stated, the photos of the snake were misleading, with the perspective making the snake appear much larger than it was.

Eastern Diamondback Facts

Eastern Diamondback Rattlesnakes are a venomous species of pit viper found only in the southeastern United States, between the east coast and the Mississippi River and south to the Florida Keys. These snakes are carnivores who prey primarily on a variety of rodents, along with a few other small mammals. Mammals are their preferred diet, though they will occasionally eat lizards and frogs. The rattlers themselves are a frequent food source for racoons , some other snakes, and several birds of prey. Eastern Diamondbacks can thrive in a plethora of different habitats, ranging from desert to woodlands, and even occasionally swamps. They are very good swimmers and can travel between islands in the Keys. Their rattles are made out of the same substance as human fingernails. Their venom can be deadly, but these snakes are not aggressive. The Eastern Diamondback’s scientific name literally translates to rattlesnake diamond.

Next Up: Are Humans Mammals?