Whenever I get a package from Amazon, my cats jump into the cardboard box as soon as I empty the contents and lay it down on the floor for them. As it turns out, fiercer cats have similar instincts, as you can see from this very entertaining video of big cats playing with boxes. Watching a lion or panther jump inside (and maul) a cardboard box is something I could watch for hours.
Some of these cats are pretty exotic. Bonus points for anyone who can name all of the animals in the video.
photo credit: Tambako the Jaguar