Boa constrictor constrictor. The boa constrictor is a large snake, although it is only modestly sized in comparison to other large snakes such as the reticulated python and Burmese python, and can reach lengths of anywhere from 3–13 feet (0.91–3.96 m) depending on the locality and the availability of suitable prey.he boa constrictor is a heavy-bodied snake, and large specimens can weigh up to 27 kg (60 lb). Females, the larger sex, more commonly weigh 10 to 15 kg (22 to 33 lb).