It. Scientists have just discovered the world's biggest snake in the Amazon rainforest. Hear about it at urban legends and stranger truths the largest snake in the world was recently discovered in the Amazon rainforest by dutch biologist and tv wildlife presenter Freak vonk. Measuring 26ft and weighing some 440 pounds, the northern green anaconda is truly the stuff of nightmares for those who are afraid of snakes. What's more, scientists have only just determined that the monstrous anaconda actually belongs to its own separate species