--Gmo loves boxes --
It does not matter what size, shape or style. When he sees a box he has an urge that he just needs to get in it.
Milk boxes (from Price Club), Blender boxes, Mailing boxes
Boxes for soda -- Which worked much better when he was a teenage kitten (top photo) than a grown monster cat (bottom photo)
He currently has a Baileys box he enjoys sitting in while staring out the front screen door to watch all the neighborhood kids, cats and dogs. And did I mention MOVING BOXES?