Here is the drawing that ends 2017: fittingly, it's Optimus Prime as well, but as an Action Master. He came with the Armored Convoy truck playset - an enormous truck that Optimus Prime drives. The cab, which sits an Action Master figure, turns into a space jet, while the trailer turns into an elaborate battle station. It was available in 1990, and marks the last of the US Generation One toys.
The combined form of the Universe Micromaster Aerialbots is Superion, an amalgamation of six robots plus their pack-in accessories that serve as connectors, head, and extremities of the gestalt warrior. While in Japan, the original source of the design ( Sixwing , 1992) was available in a collected set, this combiner needed to be purchased one bot at a time in the 2007 Universe release.