The term for an animal that primarily eats plants is "herbivore." Herbivores are specialized in digesting plant material, which often involves adaptations like flat teeth for grinding leaves and an elongated digestive tract to break down tough plant fibers. Common examples include cows, elephants, and many species of birds. Herbivores play a crucial role in ecosystems, as they help maintain plant population dynamics and serve as a critical food source for carnivores and omnivores. In various habitats, they contribute to nutrient cycling and can impact vegetation patterns by their feeding habits.