Dragon snake, Javan tubercle snake, Javan mudsnake, Rough-backed litter snake

Xenodermus javanicus

Xenodermus javanicus, also known as the Dragon Snake, Javan Tubercle Snake, Javan Mudsnake, or Rough-backed Litter Snake, is a small non-venomous, semi-fossorial snake species belonging to the monotypic genus Xenodermus. This species is best known for their characteristic dorsal scales and interesting defense mechanism in which they stiffen their entire bodies when threatened. X. javanicus is nocturnal and subsists on a diet of frogs, tadpoles and small fish. While they are known to perish once placed into captivity, some herpetoculturists have been successful in keeping them.


Xenodermus javanicus has a distinct head and long tail. The body is slender and compressed. The total length is about 50 cm (20 in). Males can be distinguished from females by examining the overall size, tail thickness, tail length, and cloacal vent for the presence of a hemipenial bulge. Females will be larger than males and have thinner, shorter tails while lacking a hemipenial bulge. Conversely, males will be smaller in comparison, have thicker, longer tails and exhibit a hemipenial bulge.



Biogeographical realms

Xenodermus javanicus is found in the Malay Peninsula (Malaysia, Thailand, and one old record from the southernmost tip of Myanmar) and parts of the Greater Sunda Islands (Sumatra, Java, and Borneo, as well as some smaller islands). It inhabits damp areas near water, including forests, swamps, marshes, and rice fields, at elevations below 1,300 m (4,300 ft), but most commonly between 500–1,100 m (1,600–3,600 ft) above sea level.

Habits and Lifestyle


Diet and Nutrition

Xenodermus javanicus subsist mainly on frogs, tadpoles and small fish.

Mating Habits

Xenodermus javanicus undergo reproduction by egg and have low fecundity (2–4 eggs).


Population number

Xenodermus javanicus are rare in the northern parts of their range, but are common in Java. There seem to be no major threats to them, and they can persist in wet agricultural lands such as rice fields. They could be potentially threatened by agricultural pollutants.


1. Xenodermus Wikipedia article - https://en.wikipedia.org/wiki/Xenodermus
2. Xenodermus on The IUCN Red List site - https://www.iucnredlist.org/species/190514/1954501

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