Adélie Penguins were the only species introduced in version 1.2.5f.
In the wild, Adélie Penguins behave like other mobs. They only spawn in Taiga biomes. If you attack an Adélie Penguin, all other Adélie around will rally around it and attack you. As with other penguins, their call lengths vary based on their health.
When right-clicking an Adélie Penguin with a raw fish, 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 Adélie Penguin by right-clicking it with shears in your hand. There is a 66% chance it will drop black and white Penguin Feathers, but a 33% chance it will become angry and attack; however, other Adélie penguins will not attack you in this situation. Note that tame penguins can be bred with wheat.
Adélie Penguins will drop 0-2 black Penguin Skins on death.