The common term for an animal that only eats plants is "herbivore." Herbivores play a crucial role in ecosystems by helping maintain the balance of plant life and serving as a food source for carnivores and omnivores. Some well-known examples of herbivores include cows, horses, elephants, and many species of birds and insects. These animals have specialized digestive systems that allow them to break down plant material efficiently, often featuring elongated intestines and specific enzymes. By consuming plants, herbivores contribute to seed dispersal and nutrient cycling within their environments, illustrating the interconnectedness of food webs in nature.