The species, which is native to Borneo, can change its epidermal colour spontaneously.

[1] The Kapuas mud snake's chameleon-like behaviour was discovered accidentally in 2005 when a specimen was put in a dark bucket.

[5] Scientists determined the snake to be a new species belonging to the genus Enhydris.

H. gyii may attain a total length (including tail) of 150 cm (59 in).

[citation needed] Like all members of the subfamily Homalopsinae, H. gyii is rear-fanged and mildly venomous.