Board Thread:General Discussion/@comment-25266931-20141008232543/@comment-24891101-20141017002103

They're not alive. Animals have souls, Grimm do not. Seems fairly straightforward. They do no need to eat, nor do they seem to take up matter. Thermodynamically speaking, that's impossible. And they don't evolve. Evolution is an undirected process; new varieties of Grimm seem to develop with the express purpose of slaying humans. There are no selective pressures to drive their evolution, as they are immortal and absurdly numerous; only occasionally dying to humans or to wild animals. Besides, they are so diverse that no amount of evolution could account for them, not in so short a timespan. Besides, since they "prey" exclusively on humans, and seem to predate humanity, they are not a biological species. Their decay processes are also not possible. They will trouble us forever, as they have since our emergence.