In the tradition of Triple Changers comes Six Changers who are, quite simply, Transformers that have six forms between which they can alternate. This was the highest level of alternate modes during the G1 era and so it is considered a rather special ability. Though only two Six Changer toys were made, thanks to Japan there are several characters from each:
You could call them Sextuple Changers, but that'd just be silly.
In US fiction Six Changers have a tendency to be portrayed as unstable. In Japanese fiction, they tend to be ninjas from the Six Clan, who are unsure of their allegiance. What this says about either ninjas or the unstable is unknown.