As described a few days ago, the original two-pack of bat-Optimus Primal and alligator-Megatron was released in Japan in 1997 as the Amazon Showdown Special two-pack. Optimus was repainted as Convobat, and Megatron as Megaligator. Rather than a realistic green hue, Megaligator is an intense Decepticon-purple. a hint of what his bio reveals: that he's supposed to be the original Megatron.
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.