Rein Snake (Gonyosoma frenatum)

Natural Distribution
  • India, South China, Taiwan, and North Vietnam
Approximate Size
  • Males 100–160 cm (3.3-5.2 ft.)
  • Females 100–120 cm (3.3-4 ft.)
Conservation Status
  • Not protected

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.


The Rein Snake was first discovered in Taiwan in 1996, in Pingdong  County, Taiwan. The majority of natural observation records have come from other locales in Southern and Southeastern Taiwan, up to 1,200 meters altitude(3).

This beautiful rat snake species has been of interest to me  for some time, however they’re not readily available. In fact, relatively few Rein Snakes are available in Canada, with the majority of North American animals being produced in the US and Europe.

Rein Snake (Gonyosoma frenatum)

  1. Gonyosoma frenatum (GRAY, 1853) – The Reptile Database (access online, July 2017)
  2. Rhadinophis frenatum – GRAY, 1853 – Reptile Care Database (accessed online, July 2017)
  3. Rhadinophis frenatum, Rein Snake – Snakes of Taiwan (accessed online, July 2017)
  4. Gonyosoma frenatum – (accessed online, July 2017)

Captive-bred Reptile Excellence