False Water Cobra

H. gigas is a large dipsadine snake that may exceed 3 m (10 ft) in length, with most adult specimens reaching about 2 m (7 ft) in length. The average weight is around 1.6 kg (3.5 lb), but some mature specimens can weigh up to 4.5 kg (9.9 lb). This species exhibits sexual dimorphism, with males being much smaller than females. The common name false water cobra is an allusion to its ability to flatten its neck, similar to a cobra, as a defensive reaction to make it look larger and more intimidating. Unlike the true cobra, though, the false water cobra stays in a horizontal position when it hoods, rather than rearing into a vertical position. H. gigas can flatten not only its neck, but also lower down its body, which is not possible for a true cobra. Additionally, the pattern and coloration of this Hydrodynastes species superficially resemble those of true water cobras (Boulengerina). The false water cobra has large eyes with circular pupils, allowing good daytime vision. The tongue is black. The background colour of a mature specimen is an olive green or brown, with dark spots and bands covering much of its body. The background coloring and banding generally become darker towards the tail. This colouring gives the false water cobra effective camouflage in its natural rainforest environment. …

H. gigas is found from eastern Bolivia to southern Brazil, and in Paraguay and Argentina.

H. gigas is primarily a diurnal species. It is also a very active and inquisitive snake, which spends much of the day climbing, burrowing, and swimming. Temperaments can vary considerably among specimens; some are docile, while others are more defensive or even outright aggressive. Many specimens are maintained in captivity, and some are even kept as pets. Captive-bred specimens can become quite tame and trusting, and many exhibit a high level of intelligence.