Simple story, obviously. The rooster is the "mascot" for a brand of Californian wine called Rex Goliath (which I'm told, incidentally, is pretty good stuff, though I've yet to try it myself). As part of a guerilla marketing campaign last month, their ad agency placed huge cutouts of "Rex" in various outdoor spaces throughout the city, including the Gallery Place Metro. My colleague picked one of these off the street and brought it to the NPR office -- and before throwing it out, asked me it perhaps I might be interested in keeping it for myself.
I still get a kick out of looking at this absurd thing throughout my workday -- in fact, from the desk you see in this video, I'm starting at its yellow beak and patriotic, gold-crusted sash right now!