The Record‑Holding Green Anaconda: Heaviest Snake on Earth

The green anaconda (Eunectes murinus) holds the title of the heaviest snake on Earth. These massive reptiles roam the waterways of the Amazon Basin, captivating scientists and the public alike with their sheer size and power.

One of the most remarkable specimens ever recorded exceeded the length of a pickup truck and weighed more than a gorilla.

The Record‑Holding Green Anaconda

Green anacondas typically range from 20 to 30 feet (6.1 – 9.1 m) long. In 2016, construction crews in Brazil claimed to have found a specimen measuring 33 ft (10 m) and weighing about 880 lb (399 kg). Subsequent investigations, however, concluded that the report was inaccurate.

In 2024, herpetologists described a new form, the northern green anaconda (Eunectes akayima). A notable individual, named Ana Julia, measured 20.7 ft (6.3 m) and weighed 440 lb (200 kg), underscoring the size potential of this lineage.

Why Anacondas Grow to Such Proportions

As members of the boa family, anacondas have evolved to become exceptionally large. The Amazon rainforest offers abundant prey and expansive waterways, allowing these snakes to reach extraordinary sizes.

They prey on sizable animals—including capybaras, caimans, and even jaguars—thanks to their powerful constriction. Their greenish‑brown coloration with dark spots provides excellent camouflage in murky waters, making them formidable predators.

Female anacondas are typically larger than males—a sexual dimorphism that benefits reproductive success.

Other Giant Snakes Around the World

While the green anaconda is the heaviest snake, other species rival or exceed it in length:

• Reticulated python (Malayopython reticulatus) – usually 10–20 ft (3–6 m) long, but can exceed 30 ft (9.1 m). The longest recorded individual measured over 32 ft (9.75 m).
• Burmese python (Python bivittatus) – can reach 23 ft (7 m) and weigh around 200 lb (91 kg). In Florida, they are an invasive species disrupting local ecosystems.
• Yellow anaconda (Eunectes notaeus) – typically 5–12 ft (1.5–3.7 m) long, but can grow up to 15 ft (4.6 m) and weigh over 100 lb (45 kg).
• African rock python (Python sebae) – reaches 10–16 ft (3–4.9 m) and can weigh up to 200 lb (91 kg), making it Africa’s largest snake.

We created this article in conjunction with AI technology, then fact‑checked and edited by a HowStuffWorks editor.