Board Thread:Episode Discussion/@comment-23712247-20160203074906/@comment-109.153.36.227-20160225131839

The Grimm may not be connected to the moon at all. I hearby put it to the jury that it was the first Dust users who made them. They tried to make themselves perfect by removing all their bad qualities but created the Grimm by mistake. They only told other people about Dust when the Grimm started attacking, leaving out the part where they were to blame.

And before anyone says it, yes I know that the Legend says that the Grimm appared before Dust was discovered but there's a difference between Legend and History.