A Transformer who has three modes: a robot, an aircraft, and a land (or in one case, water) vehicle. (Each Transformer was generally limited to one vehicle mode.) Two were introduced to the Decepticon lineup in 1985 and four more were added to both the Autobot and Decepticon sides in 1986.
The Decepticon Triple Changers were Astrotrain, Blitzwing, and Octane. The Autobots were Broadside, Sandstorm, and Springer.