It's an ice cream truck.
LP's unicorn from Nannie and Grandpa came in a big box. The other morning I pulled the big box into the living room, handed LP her markers, and asked her what the box was.
She started off by coloring a river and an ocean inside the box while I drew her a steering wheel. She added her baby's carseat and drove off for a while, driving over me a couple of times in the process. The car turned into a boat when she came to the river and needed to cross over. Then it became an airplane so she could go to see Nana and PopPop.
When Uncle Dave stopped by, the box became an ice cream stand that quickly grew tires and became an ice cream truck. It's not a very well stocked ice cream truck though, it only gave out chocolate ice cream for a while. Apparently all the vanilla ice cream belongs to the driver and it never carries peppermint. I was eventually able to get a cherry popsicle after adding one to the menu.
In the evening, the box was turned on its side and the inside bottom became a work of art from one end to the other. Who needs toys when 1 cardboard box can provide an entire days worth of imagination and play.