Herbivorous comes from the Latin word herba, which means “green plants,” and that’s what herbivorous animals eat all the time: grass, leaves, and other plants. Some massive and strong animals actually have peaceful herbivorous eating habits, like gorillas and hippopotamuses. The opposite of herbivorous is carnivorous, which describes meat-eating beasts like lions, sharks, crocodiles, and your uncle Marvin who eats nothing but steak all day long.