a few days ago, a giant reptilian monster attacked the city of new York. When the army was trying to fight it, it shot off it's own dorsal plates before growing them back. One of the launched ones landed just behind your backyard.

Now you are getting ready to move somewhere else until the city is ready to be inhabited when you start hearing a twisted sound of... crying? It was coming from outside so you go out the back to see a strange creature with it's back attached to the dorsal plate. It seems to be source of the twisted crying.