Hydrodynastes gigas, commonly known as the false water cobra, is a large, semi-aquatic snake native to South America. It thrives in wetlands and forests, exhibiting a unique neck-flaring behavior when threatened, mimicking true cobras. With a diet of fish and amphibians, it plays a vital role in controlling prey populations.

Hydrodynastes gigas, commonly known as the false water cobra, is native to South America. Its geographical distribution includes countries such as Brazil, Bolivia, Paraguay, and Argentina, primarily within the central and southern parts of these countries.

The false water cobra typically inhabits areas that are near bodies of water, such as rivers, streams, and marshes. It thrives in warm, humid environments, which are characteristic of tropical and subtropical regions. The species is often found in lowland forests, savannas, and wetlands where water is a prominent feature of the landscape.

Hydrodynastes gigas is a semi-aquatic predator that primarily feeds on amphibians, fish, and small mammals. Its ecological niche is closely tied to its ability to hunt both on land and in water, utilizing its speed and agility. The species has adapted to both terrestrial and aquatic habitats, enabling it to exploit a variety of prey and environments within its native range.