Mamushi

The Mamushi is a small pit viper, commonly around 45–60cm long, with a maximum reported length of 91cm. Its triangular head is clearly wider than the neck, and its eyes have vertically slit pupils. Body colour varies from grey-green and pale green through rust-red and brown to nearly black. (Wikipedia, general species account)

Current taxonomic sources restrict Gloydius blomhoffii principally to Japan, with occurrence also confirmed on Kunashir Island. Populations formerly attributed to this species in China and Korea are now assigned to Gloydius brevicauda or related taxa. It produces live young rather than laying exposed eggs. Consequently, the supplied China record and the duplicate Agkistrodon combination should not be accepted without correction. (The Reptile Database)