The heaviest snake is the ANACONDA, which has 8 letters. Anacondas are a group of large snakes found in tropical South America. They are non-venomous constrictors and can grow to be quite large, with some specimens reaching lengths of up to 30 feet. Anacondas are semi-aquatic and are known to inhabit swamps, marshes, and slow-moving rivers. They are also excellent swimmers and have been known to hunt prey in the water.