Achalinus

Achalinus (common name: odd-scaled snakes) is a genus of harmless snakes in the family Xenodermidae. Species of the genus are found in China, Japan, Taiwan, and northern Vietnam. Ten species are recognized as being valid. Achalinus was previously placed in Colubridae (along with other xenodermids). The nickname "odd-scaled" is because their dorsal scales do not overlap one another as in most snakes, but instead are spread out and lie individually similar to pieces of a puzzle. Odd-scaled snakes are known to be burrowers that crawl below the fallen leaves of the forest.