The longest snakes in the world are the Reticulated Python, a medium-build python that lives in the rainforests of Southeast Asia, and the Green Anaconda of the Amazon. One source (Oliver 1958 and Gilmore and Murphy 1993) reported a Green Anaconda with a length of 11.5 meters (37.7 ft), but its validity has been questioned and the value is impossible to verify. Some biologists dispute this, putting the maximum anaconda length at 9.5 meters (31.1 ft). Either way, the Green Anaconda is still probably the heaviest of the world's snakes, with the largest known specimens weighing over 50 kg (110 lb).
All reports of anacondas larger than 10 meters in length should be regarded with caution. Anaconda snakes of as long as 15-18 m (50-60 ft) were reported sporadically since the colonization of South America by Europeans, but these claims are highly uncertain. Since the early 20th century, the Wildlife Conservation Society has offered a $50,000 USD (US Dollars) award for any anaconda over 9.1 meters (30 ft) in length, but this prize has never been collected. Still, the prospect of giant snakes has fueled the public imagination for decades, as evidenced by movies such as Anaconda.
The longest well-documented snake is the Reticulated Python from Southeast Asia. The longest specimen was 10.7 meters (35.1 ft), and this value is agreed upon by biologists. This is the only snake absolutely confirmed to be over 10 meters in length. Large reticulated pythons are voracious predators. As a rule of thumb, these snakes can swallow anything less than 1/4 their own length, and up to their own weight. As such, some reticulated pythons have been observed eating viverrids (e.g., civets and binturongs), primates, and even one relatively sickly 43 kg (95 lb) Sun Bear, which took two and a half months to digest.