What Is the Biggest Snake in the World? - Animals | HowStuffWorks

"[Females] grow longer than males in both the reticulated python and the anaconda, so the biggest snake in the world (wherever she is) is doubtless a female," notes Shine. "In terms of length, it will be a reticulated python in Asia, but that snake will be massively outweighed by some beautiful senora in South America."

"The question of size is a tricky one," says Rivas. Imagine if someone asked you, "What's the largest land mammal?" According to Rivas, you would "answer before hesitation" that it's the African savanna elephant.

"Nobody would start belly aching as to how much taller giraffes are. Simply because when we mean size, mass is the determining factor," he says. "That is why I simply say anacondas are the largest snakes in the world, period."

OK, but — how big do they get?

Exact measurements are hard to pin down. Green anacondas — and retics — are incredibly strong beasts. Not only that, but the snakes don't always react well to handling. So, anybody who might want to stretch one out by hand and hold it up to an extra-long ruler sure has their work cut out for them.

Rivas' book, "Anaconda: The Secret Life of the World's Largest Snake," contains some interesting anecdotes about this.

In one chapter, he describes a colleague who measured a full-grown anaconda at 18 feet (5.5 meters). To get this figure, the scientist took a piece of string, held it over the struggling reptile's back and then measured the string.

Later, Rivas himself measured the same anaconda using the exact same technique — and found the creature to be just 14 feet (4.3 meters) long. Simply by twisting its body around, the snake managed to yield two very different measurements.