This rare scooter from 1969 is a re-imagining of a design that originated in 1928. It's an eccentric-hub scooter that is powered by the rider bouncing up and down on the platform, using their momentum to drive the off-center rear wheel.
 
With its synamic form the stying is reminiscent of the famous Schwinn Stingray "Crate" bikes, but the Kangaroo scooter is far more uncommon.
 
This example is in very good condition and appears entirely original.