Jack Barricade's Clues

Or he could have been taken by a flying creature made of stone. Thus, being able "to see everything".

It couldn't have been a flying monster since it was described as a stone golem. That's a pretty specific type of monster. The statue fits that name easily but who knows. I don't know if that statue is a boss or a monster or what. But to me it looks like it is something significant. It doesn't just look like another background object. If anything it sticks out from the background.