Xiaoheishan Slug-eater Snake

The Xiaoheishan slug-eater snake (Pareas nigriceps) is a small, harmless snake native to the Gaoligong Mountains of Yunnan, China. It is easily told from other Pareas by the large black oval on top of the head and the two rounded black spots on each side of the head, which are separated from the nuchal band. (The Reptile Database; Wikipedia, general species account)