Baby, (Joey) Kangaroo and Wallaby.
Kangaroos are usually larger than wallabies.
The kangaroo has legs which are too long between the knees and the ankles. This makes the legs kind of oversized with respect to their body. The wallaby has more compact legs which are shorter.
The wallaby generally has a bright and colorful coat, with splashes of different colors. The coat of a kangaroo is less shiny and they have sober colors like black and grey. The kangaroo does not have premolars and the crowns are less prominent. The wallaby does have premolars and a more pronounced cutting tooth. The kangaroo generally feasts on grasses because it lives in open treeless areas. The wallaby on the other hand, eats mostly leaves because it lives in forest areas.