The black-headed python is a slender, shiny snake with a jet-black head and neck. The black pigment ends abruptly, and the rest of the body has narrow, wavy bands of brown on a tan background. Unlike most members of the family Pythonidae, the snake lacks the heat-detecting facial pits used to locate warm-blooded prey. Although it preys on small mammals and ground birds, it specializes in eating other snakes, including venomous snakes and snakes of its own kind. It is of a mild disposition, however, and is easily tamed in captivity.

A slightly larger relative called the woma (Aspidites ramsayi) is very similar in appearance and habits but lacks the black head. It inhabits semidesert regions of Central Australia, sheltering from the heat in animal burrows or thick bushes.

Both Aspidites species mate in winter and lay clutches of fewer than a dozen large eggs. Females coil around the eggs and incubate them for two or three months. Hatchlings average more than 2 feet (0.6 meter) in length. Some woma juveniles have a black blotch on the snout that disappears as they mature. (See also Pythons.)