The O-2 Skymaster airplane is a military version of the Cessna 337 Super Skymaster.
An O-2 Skymaster
Front corner view of an O-2A Skymaster
Front view of an O-2A Skymaster
Side view of an O-2A Skymaster
A US Air Force Skymaster in flight
An O-2B Skymaster dropping leaflets
O-2A Super Skymaster at Castle Air Museum in Atwater, California