Capybara

The capybara is a rainforest animal who has adapted to its environment many ways, they developed a semi aquatic lifestyle giving certain advantages to living in the rainforest like their webbed feet, ear placement, and many more. I think that with gills as well as lungs would be perfect for the capybara, because of the capybara's natural habitat allowing it to be a more versatile animal, and helping it hide from jaguars. As well as helping it with its diet and ability to find food in the water. And because of the ability to find more food the capybara population could potentially grow because of the availability of resources. Thus diversifying the species of capybaras and making them more common.