In the wild, Rockhopper Penguins behave like other animals. They only spawn in the ocean biome. When attacked, all other Rockhopper Penguins around will get mad and attack you. Their call lengths vary based on their health.
When right-clicking any Rockhopper Penguin with a fish (raw, salmon, or puffer), there is a 1/3 chance it will be tamed, even if it is angry. Tamed penguins wear red bow ties. You can shear a tamed Rockhopper Penguin by right-clicking it with shears in your hand. There is a 66% chance it will drop black or white Penguin Feathers, but a 33% chance it will become angry and attack; however, other penguins will not attack you in this situation. Note that tame penguins can be bred with wheat.
Rockhopper Penguins will drop 0-2 black Penguin Skins on death.