Tropidoclonion is a genus of snake in the subfamily Natricinae of the family Colubridae. The genus is monotypic, containing the sole species Tropidoclonion lineatum, commonly known as the lined snake.

Snakes are elongated legless reptiles of the suborder Serpentes. Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group