Burmese pythons are dark-colored snakes with many brown blotches bordered in black down the back. The perceived attractiveness of their skin pattern contributes to their popularity with both reptile keepers and the leather industry. The pattern is similar in colour, but different in actual pattern from the African rock python (Python sebae), sometimes resulting in confusion of the two species outside of their natural habitats. The African rock python can generally be distinguished by its tighter pattern of markings, compared to the Burmese python, which has bolder patterns, similar to those seen on a giraffe.
In the wild, Burmese pythons grow to 3.7 metres (12 ft) on average, while specimens of more than 4 metres (13 ft) are uncommon. In general, individuals over 5 metres are rare. The record maximum length for Burmese Pythons is held by a female named “Baby”, that lived at Serpent Safari, Gurnee, Illinois, for 27 years. Shortly after death, her actual length was determined to be 5.74 metres (18 feet 10 inches). Widely published data of specimens that were reported to have been even several feet longer are not verified. There are dwarf forms on Java, Bali and Sulawesi. On Bali they reach an average length of 2 metres (6.6 ft), and on Sulawesi they achieve a maximum of 2.5 metres (8.2 ft).