Kangaroos and emus are two animals that cannot walk backwards. Kangaroos are large, hopping mammals from Australia that carry their offspring in pouches. During saltation, their hopping movement, kangaroos push off with both large feet at the same time, and they use their tails for balance. The combination of their muscular legs, big feet, and tails may help kangaroos move forward effectively, but these appendages also prevent them from going in reverse. Emus, on the other hand, have a thick, long, and muscular tail that is not very flexible and often acts as the third leg. Their feet are also big and muscular and are designed to move in a forward direction effectively and prevent the backward movement. However, emus can move slightly backward in a rearward motion only during a fight to avoid injury. It is worth noting that while some sources may include alligators and penguins in the list of animals that cannot walk backwards, these animals have special adaptations that enable them to move forward, though their backward movement may not be defined as walking.