Penguins are a species of flightless bird found in the Mario franchise. They are good swimmers and often inhabit cold climates, like their real-world counterparts, to which they bear varying degrees of resemblance, depending on the game. Many also inhabit tropical areas, as seen in Super Mario Galaxy and Super Mario Galaxy 2. Most of them do not hurt Mario, though they sometimes act as obstacles or hindrances to his quest. Benevolent penguins often speak with Mario, sometimes asking for his help or offering him a service.
Penguins from the Mario franchise are colored a moderate dark shade of blue with white bellies, making them similar to Bumpties. They also resemble little penguins, also colored dark blue. In some games, the back of their heads is tapered by a small crest. However, the Penguru and Coach are colored similar to king penguins.