Gonyosoma jansenii

Gonyosoma jansenii, commonly known as the Celebes black-tailed rat snake, the Celebes ratsnake, and Jansen's rat snake, is a species of snake in the subfamily Colubrinae of the family Colubridae. The species is endemic to the Indonesian island of Sulawesi.

Etymology
The specific name, jansenii, is in honor of Albert Jacques Frédéric Jansen, who was an administrator in the Dutch East Indies.

Habitat
The preferred natural habitat of G. jansenii, is forest, at altitudes from sea level to 1,000 m.

Description
A long snake, G. jansenii may attain a total length of 199 cm, which includes a tail length of 45 cm. Adults are olive or yellowish brown on the anterior and middle portions of the body, with some scales black-edged. They are entirely black on the posterior portion of the body and tail (Boulenger, 1894).

Behavior
G. jansenii is semi-arboreal.

Reproduction
G. jansenii is oviparous.