Penguins were birds that lived in cold or wet places. They mostly gathered in polar regions. Antarctica was often associated to penguins due to their presence on the continent. (PROSE: EarthWorld)
Penguins mated for life and often appeared on greetings cards. (TV: Something Borrowed)
History
When they were first discovered, they were noted by sailors for their visual similarity to the Great Auk, and were so named penguins. The Great Auk's name was changed, following this. (AUDIO: Last Chance)
In 1970s London, the Third Doctor and the Brigadier encountered penguins at a zoo. They had dived into their pool to escape a flock of parrots which were attacking them, but the penguins attacked them as well. (COMIC: The Arkwood Experiments)
In 2048, Patricia Audley had a pet penguin, which she named "Poopsie". (COMIC: Blood and Ice)
In 7214, specimen of penguins were held in a nature preserve in Antarctopolis, Antarctica having been urbanised. (COMIC: Façades)
Sky penguins lived in the ice clouds of New Earth. (AUDIO: The Skies of New Earth)
The Twelfth Doctor and Clara Oswald once had an adventure that involved them carrying a penguin as three others chased them. (COMIC: The Day at the Doctors)
References
Liv Chenka said that River Song, in her psychic wimple, looked like a sexy penguin. (AUDIO: The Doomsday Chronometer)
One of the TV shows Cal watched in her dream world was about penguins. (TV: Silence in the Library)
The Tenth Doctor insisted that the North Pole did not have penguins, contrary to popular belief. (PROSE: The Frozen Wastes)
Bill described the Twelfth Doctor's running as "a penguin with its arse on fire". (TV: The Pilot, Smile)
Frobisher
Frobisher took on the form of a penguin as his wife Francine had been fond of them. He occasionally changed between variations of the species. (COMIC: Voyager)
Alternate timelines
In an alternate timeline, penguins lived on the River Nile in Egypt. (TV: The Big Bang)