Board Thread:Speculation House/@comment-71.17.68.254-20130907025506/@comment-23784953-20130912112140

Darkcloud1111 wrote: There is something else I noticed. So Grimm are formed in possibly one of three ways:
 * 1) They take control of native animals and mutate them over time.
 * 2) They breed and make more Grimm.
 * 3) (Maybe) There is some kind of intelligent design going on, with Grimm being born from a single intelligent source Grimm.

However looking at option #1, you have to wonder why it is that we haven't seen any human Grimm. I mean maybe Adam is one, but his mask seems more like just a mask he wears as it has holes in it he can look through. The other Grimm either have no eyes or their eyes are part of the mask. Maybe we just haven't seen it yet or maybe Grimm just don't like us. I'd like to re-affirm your theory #1.

It's likely that humans aren't easily corrupted due to the nature of their soul.

It's possible most animals have no knowledge on how to use their Aura (all based on Pyrrha's statement that even animals have souls), making them defenseless against the corruption of the Grim.

Humans are not as defenseless as them, they can use their own light to resist the Grim's corruption.

Of course, this presents the possibility that maybe there may be an example of a human willingly be corrupted by the Grim much later on.