Penguin gait is commonly called waddling.
Penguins, unlike many other terrestrial animals, exhibit a significant amount of side-to-side (frontal plane) motion when they walk. This characteristic movement is what defines their waddling gait. The waddle arises from their anatomy, particularly their short legs positioned far back on their bodies, which is ideal for swimming but less efficient for walking on land. This unique anatomy leads to the distinctive swaying motion observed when penguins move across land.
