Young wallabies are called joeys, and both males and females will want to play-box. While cute when they're young and small, this behavior can grow into an obnoxious habit after they reach their full height of 2 ½ to 3 feet, and 30 to 40 pounds in weight. Although females lose interest in this type of play as they get older, the males love it. In fact, if you don't discourage boxing while they're young, a male wallaby will delight in pummeling you even more as he gets older.
To learn more, read Unusual Pets – Wallabies