When you’re an anaconda you don’t need venom to take down your prey, even if its the world’s largest rodent, a capybara, weighing somewhere in the neighboorhood of one hundred pounds!
See all National Geographic videos: http://video.nationalgeographic.com/video/?source=4001
It can weigh 250 kg 550 lb and have a girth of more than 30 cm 12 inches in diameter.