Arise, Pretenders! (but only in Japan)

One of the great tragedies of the cancellation of the animated series in the United States was that fans never had a true opportunity to see the 1988 characters in animated form outside of commercials. Super-God Masterforce in Japan rectified this. One really unique sub-group of Transformers were the Pretenders. They were Autobots and Decepticons with the ability to not only transform into vehicles, but they had outer organic shells to disguise their inner robots. Talk about robots in disguise! In the series, the Pretenders took on shells and could displace their mass to change size. Although only the Autobot Pretenders did this, I assume the Decepticon Pretenders could do the same thing. The Pretenders played a large role in the series until the appearance of the God-Masters (Power Masters). After that, they were still active, but took more of a backseat (excluding Metal Hawk).

In the U.S., the Pretenders did appear in the comics, but the concept was kind of ridiculous as the shells made the Autobots look like 4o foot tall humans, and somehow they managed to blend in to society. The cool part was that they could separate from their shells, and then they could remote control their shells to fight beside their robot modes.