What is the world’s largest living snake by mass, found in South American rainforests?

The green anaconda is the world’s largest living snake by mass and inhabits South American rainforests.

Green anacondas live in slow-moving waters and wetlands across northern and central South America. Their heavy bodies are adapted to swimming, and the eyes and nostrils sit high on the head so the snake can watch and breathe while mostly submerged. Females are substantially larger than males.

The species kills prey by constriction rather than venom. It eats fish, birds, turtles, capybaras, and other animals, using ambush tactics in murky water. Anacondas give birth to live young instead of laying eggs, a reproductive strategy shared by several boas.

The reticulated python is often described as the longest snake, so “largest” needs clarification. Green anacondas are generally regarded as the heaviest living snakes, while exact maximum measurements are difficult to verify because exceptionally large historical claims were often exaggerated.