The cuddly shape and peaceful demeanor of the capybara seems out of sync with the brutal, anaconda-eat-jaguar world of the Amazon. Troops of capybaras can be seen munching on the lush grasses and aquatic vegetation at the banks of most rivers.

At the first whiff of danger, these timid animals scurry into the muddy water and sink like submarines out of sight. Though they are mammals, they can hold their breath underwater and even sleep underwater, their snouts barely protruding above the surface.

The capybara, which in Guaraní means “master of grasses,”is the largest rodent in the world. It grows to about the size of a large pig and is covered with a thin layer of reddish brown hair. It has small ears and nose, and eyes that are perched at the top of its barrel-shaped snout for easy use while swimming. Though clumsy on land, capybaras are agile swimmers thanks to their webbed toes.

Capybaras are prized bush meat among Amazon natives and a food source for anacondas, big cats, harpy eagles, and caimans. Despite all the hunting, the capybara remains common thanks to its rapid reproduction. Females begin mating in the water a year after they are born and have 2–8 babies at a time. Capybaras can live up to 10 years.