These anacondas are olive-green with dark oval spots along their spines and similar spots with yellow centers along their sides. The scales on their belly are yellow and black. They also have two dark stripes from their eyes angling toward their jaws. They can reach lengths of 30 feet, diameters of 12 inches, and can weigh 550 pounds. They're not particularly aggressive, and as such they're not too dangerous towards the unsuspecting. They're among the largest snakes in the world.