The Cozy Mark IV is a 4-seat single engine homebuilt light aircraft designed by Nat Puffer. The aircraft is built from plans using basic raw materials. It is not a kit aircraft though many small parts are available prefabricated. The Cozy is similar in design and construction to the 2-seat Rutan Long-EZ. It is a derivative of that aircraft designed with approval from Burt Rutan.
It is the successor of the Rutan Long-EZ .