They are non-venomous snakes and use constriction to kill their prey, they wrap coils of their muscular body around the prey and squeeze until it suffocates or dies of injuries received from been constricted. They are not fussy eaters and will eat almost anything they can over power, including fish, reptiles, birds and mammals. The anaconda has the ability to stretch its jaws to swallow large prey, whole, as they are joined together by an elastic ligament, digestion is slow and a large meal will last a snake weeks if not months.
The largest wild recorded green anaconda was by Dr. Jesús Antonio Rivas, who has had the opportunity to examined thousands of anacondas, was a female measuring 521 cm (17.09 ft) long and weighing 97.5 kg (215 lb). A green anaconda that was keep in captivity, Pittsburgh Zoo and PPG Aquarium, reached a length of 6,27 m (20.6ft) at the time of its death. The weight of these snakes can change dramatically based on when they last fed and what they ate. The females of this species are larger than the males. There have been reports of much larger snakes but none verified, it must also be taken into account that the skin of the snake can be stretched after been removed. The Guinness Book of World Records has reported that this snake has probably had more extreme size exaggerations than any other living animal to date.