Javan Odd-scaled Snake

The dragon snake, also called the Javan tubercle snake, Javan mudsnake or rough-backed litter snake, is a small, non-venomous, semi-fossorial snake and the only species in the genus Xenodermus. It is best known for its characteristic dorsal scales and for a defence in which it stiffens its entire body when threatened. It is nocturnal (Wikipedia, general species account).