Board Thread:Speculation House/@comment-25045079-20140815193846/@comment-101.162.10.10-20141018043236

According to the recent episode of World of Remnant, the Grimm have a devolpment process.

When they are formed/ born they have no outer bone-like features due to only being recently formed. Whilst in their young phase they are reckless and just charge head on.

But as Grimm grow older, they start to sprout bone-like features. Their bone-like features and bodies grow over time as well.

The Grimm that attacked Ruby in her tralier were young Grimm, their youth is refleted in their recklessness as they continued to attack Ruby even though they saw their herd members being sliced in front of their very eyes.