This is a large snake, with females reaching 150 cm (59.1 in) in total length (body + tail) and males a little less. Sizes vary among different populations, with M. l. lebetina being somewhat smaller.The head is broad, triangular, and distinct from the neck. The snout is rounded and blunt when viewed from above, which is why it is also called the blunt-nosed viper. The nasal and nasorostral scales are almost completely fused into a single plate, although some variation occurs.