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Rein Snake

The Rein Snake (Gonyosoma frenatum) is a non-venomous reptile species belonging to the family Colubridae. It is known for its vibrant coloration and arboreal nature. Below is the requested information about the Rein Snake:


  • Gonyosoma frenatum (CHEN et al. 2014)

Common Names

The Rein Snake is commonly known by the following names:

  1. Rein Snake
  2. Green Tree Racer
  3. Asian Green Racer
  4. Khasi Hills Trinket Snake

Natural Distribution

The Rein Snake is native to Southeast Asia and can be found in various countries, including Thailand, Malaysia, Indonesia, Vietnam, and Cambodia. Within these regions, it inhabits forests and woodland areas, often preferring arboreal environments.

Conservation Status

  • Least Concern (LC)

The IUCN Red List of Threatened Species in 2011 listed Gonyosoma frenatum listed as Least Concern.


Size: The Rein Snake is a medium-sized snake, with adult individuals typically reaching lengths of 3.5 to 4 feet (1.0 to 1.2 meters).

Coloration: They have a vibrant green coloration, which serves as camouflage in their arboreal habitat. Some individuals may have a bluish tint on their scales.

Body Shape: They have a slender and elongated body, allowing them to move swiftly through the trees.

Scales: The scales of the Rein Snake are smooth and glossy.

Head and Eyes: They have a relatively large head with distinct eyes and a pointed snout.

This medium sized colubrid has a long and slender body that is laterally compresses. The head is slightly triangular, with pointed snout, and has a prehensile tail. Female Gonyosoma frenatum can attain slightly longer lengths and are slightly heavier bodied than males.

Ontogenetic color change (change of color from neonate to adult) ranges from grey or brownish colored neonates to bright green or even turquoise adults.

The eyes are medium-large as seen I’m many of the Gonyosoma species and is typically cream to yellow in color with black pigment anteriorly and posteriorly.

Rein Snake Gallery


  1. Khasi Hills Trinket Snake, Gonyosoma frenatum, The IUCN Red List of Threatened Species (accessed online 2023)
  2. Gonyosoma frenatum (GRAY, 1853) – The Reptile Database (access online, July 2017)
  3. Rhadinophis frenatum – GRAY, 1853 – Reptile Care Database (accessed online, July 2017)
  4. Rhadinophis frenatum, Rein Snake – Snakes of Taiwan (accessed online, July 2017)
  5. Gonyosoma frenatum – (accessed online, July 2017)