A kangaroo is a mammal.
Mammals are warm-blooded animals that have fur or hair and typically give birth to live young. They also have mammary glands that produce milk, which is how they feed their offspring. Kangaroos belong to a group of mammals known as marsupials, which means that they carry and nurse their young in pouches. While amphibians, such as frogs and salamanders, begin their lives in water and usually have a two-stage life cycle, kangaroos have a completely different lifestyle and reproductive system. Thus, kangaroos are firmly classified as mammals, distinguished by their unique features that allow them to thrive in their environment.