Dog barks, whines and begs to lick pizza box. W4D puts box on the floor. The Beastie Boy crawls in to get all the cheese and crumbs, then insists on having his dinner kibble in the box.
Beast thinks pizza box with "window" is cool.
Beastie refuses to leave pizza box.
And yes, he needs a bath. If you ate dinner in a pizza box, you would need a bath, too.