Kangaroos (カンガルー, Kangarū) are a species of villager in the Animal Crossing series. All female kangaroo characters have joeys in their pouches. The joeys in their pouches will move their mouths at the same time their mother does, as well as mimic other motions and genstures. Kitt and Mathilda are the only kangaroos to appear in every game to date. There are no jock, lazy or smug kangaroos.
All kangaroos' initial catchphrases relate to their joey. For example, Kitt's initial catchphrase is "child," and Mathilda's is "wee baby."
Originally, all kangaroos were female. However, two male kangaroos were added in Animal Crossing: New Leaf. Kangaroos are one of the few species to have a slightly different model for each gender, such as cows and bulls (cattle), and deer.
This might be expected from the fact that flyers (females) have joeys, while boomers (males) do not.