'Ancient stone mimic
This monster was known as the human hunter by ancient humans. They would follow traces of ancient humans due to the fact that the iron and other earth related elements within their blood were delicious to them.
They can survive for thousands of years in dormancy while mimicking stones or statues, they will always be identifiable by the red markings on their body though. These red markings form from the human bodies that they have consumed, some ancient humans believed this was the world cursing them as a horrendous monster undeserving of further growth.
They will often be brought in to ancient human settlements as stones for building. From there, they will take the form of a statue or another human in stone form to hide in plain sight. Over the course of months or years, they will move and kill humans to eat before resting again in wait.