The Cobra S.N.A.K.E. Battle Armor was released in 1983. It didn't come with a figure, but was meant to fit around existing figures.
The armor was supposed to be used by Cobra, but would 'brainwash' any member of the G.I.Joe Team that wore the armor, and make them fight for Cobra.
The playset/vehicle came with accesories (including interchangeable hand weapons), stickers and blueprints.