[3] It is found in central and northeastern India, Bhutan, Nepal, and Pakistan.

As the common name implies, the dorsal surface of the head, including the nape of the neck, is black or dark brown, followed by a thin yellow nuchal collar.

On each flank there is a thin black stripe separating the differently colored areas.

A series of small black dots, widely separated, run down the vertebral row of dorsal scales.

The smooth dorsal scales, which lack apical pits, are arranged in 17 rows.