Wallabies are marsupial mammals with a generally upright, plantigrade posture with elongated, powerful hind legs in line with powerful fourth toes which allow for sustained and swift bipedal hopping, balanced by a heavy tail. Many are in the same genus as kangaroos, and in these cases the only real distinction between them is that wallabies are smaller. However, many species of various genera are also called wallabies.
Because such a wide range of species are called wallabies, many are more closely related to species that have broad hind feet and only limited hopping ability than the kangaroos all wallabies resemble. Nonetheless, all wallabies are able hoppers at high speeds. At lower speeds, they do not hop, instead moving by supporting themselves with their forelimbs and tail while moving their hind legs forward, then shifting the body.
Wallabies are herbivores with many-chambered stomachs for the digestion of cellulose. Some species regurgitate food to be chewed again and swallowed in a way similar to placental ruminants chewing their cud. They are grazers and browsers, eating grasses and leaves in a variety of environments. They have well-developed lower incisors that impact a tough pad on the roof of the mouth when the mouth is closed, rather than the upper incisors. They also have large molars for grinding plant matter.