Oh, here's a heart-warming tale of a friendship between a bird and a porcupine animated by David Chao. Then why is it called "Pig Box"? (I had to Google the answer to that one.) I don't even know why the pig/porcupine didn't break into a rendition of "Hakuna Matata" like I kept expecting him to. -- that question I don't think can be answered properly.
But you should watch the video -- perhaps you will come up with a better answer than I've been able to provide.
"Pig Box" [Vimeo]