Board Thread:General Discussion/@comment-3257939-20140105070225/@comment-24374466-20140302231040

Personally, I've been working on the idea that Grimm are essentially normal animals as far as their behavior. The idea of an overarching Grimm entity, mentioned in the speculation, is what drives them against humanity. As the contributor above said, the Grimm seem to have existed first and then humanity came along and started claiming territory.

To take it a step further, I even have the idea that the creatures of Grimm are merely corrupted animals that are forced to fight because their races have already lost against the Grimm.