C139 Who is the monster?

I felt my scalp tingle as I looked at the empty shell in front of me, which had no skeleton and no flesh.

How could this be? Not long ago, the Fat Monk was still fine, why is there only skin and bones left?

Could it be the red goat from earlier? Was it the monster that ate the flesh and blood of the Fat Monk?

The more I thought about the strange sounds I heard earlier