What is a large mammal living in the amazon river?

Capybara

The capybara (Hydrochoerus hydrochaeris) is the largest rodent in the world. It is native to South America and is found in countries such as Brazil, Peru, Venezuela, and Colombia. Capybaras are semi-aquatic animals and spend most of their time in or near water. They are herbivores and their diet consists mainly of grasses, aquatic plants, and fruits. Capybaras live in groups of up to 100 individuals and are social animals. They are known for their friendly nature and are often kept as pets.