Board Thread:Speculation House/@comment-4830106-20130810030606/@comment-10390252-20140511074855

I, personally, think that the Grimm are one of two things:

1) Some kind of artificial pseudo-life created as a weapon by an unknown power and abandoned on the planet long ago; they're now wandering around Remnant trying to fulfill their program without much in the way of central co-ordination (if anyone worked out how to do that...? Bad times);

2) Some kind of ecological immune response to humanity.