The 456 Adventure Suggestions

[Deleted]

I plan to in the future soon have my PCs encounter the the race of beings known only as the 456 in an upcoming adventure. Without just playing through Children of Earth (although I still am convinced that would lead to interesting results) does anyone have suggestions to as what adventure the 456 could be a part of? Or either any suggestions for planet of origin or society?

[da professor]

I have always strongly suspected that the 456 are the Macra, as the are both huge crablike creatures who breathe air pollution.