Anacondas may grow to more than 25 feet long and weigh more than 500 pounds. Females are larger. At its thickest point, anaconda can measure a full foot thick. They are the heaviest snakes in the world (though not the longest). Their eyes and nostrils are on top of their head so they can swim along the surface of the water. Their mottled brown color helps them blend in (camouflage). They coil in or near the water and wait for prey to come down to drink. They will grab prey and drown it before eating it. They can swallow prey much larger than the size of their mouth because their jaws can unhinge to take in the larger prey.