Found from Mexico to Paraguay, this is one of the most well-known snakes, and has been popular in zoos for well over a century. It is also common in private collections. While it has a reputation as a giant, it actually rarely reaches 14 feet, and has never been documented to reach 20 feet. In contrast to the much larger Anaconda, it is not dependent on water in its environment, though it swims quite well. A nocturnal animal, it is often motionless during zoo visiting hours.