KANGAROO, n. An unconventional kind of animal which in shape is farther than any other from being the square of its base. It is assisted in jumping by its tail (which makes very good soup) and when it has happened to alight on the surprised Australian it is usually observable that his skin is unbuttoned from the neck downward and he carries his bowels in his arms.
2007 Update: A reverse pachyderm of the southern hemisphere designed to demonstrate the coriolis effect. The kangaroo demonstrates the intelligent hand behind the origin of species, as had it evolved in Kansas rather than Australia, the kangaroo likely would have entered politics rather than pugilism.
A joke heard in central Queensland: A man who had grown up alone in the outback sent to Sydney for a wife. When the woman arrived she found an empty house with furniture placed outside in front. She asked the man why he didn't live in his house and he replied "I put the furniture outside this morning. If you're anything like a kangaroo, I figure we'll need plenty of floorspace."