Plant-eating.
Example:
In spite of their frightening appearance, marine iguanas are peaceable herbivorous animals that feed mostly on seaweed.
While many herbivorous animals (such as rabbits and cows) are noted for their passive ways, such behavior is not universal among herbivores. A rhinoceros is herbivorous but capable of inflicting serious damage if threatened. Among dinosaurs, the herbivorous Diplodocus had a thick tail that could be used as a lethal weapon against attacking carnivorous enemies.