No, really, it's an airplane!

It's an airplane... to carry other airplanes!  The first plane we saw land after our arrival at Paine Field in Everett, WA on July 26, 2014 was the Boeing Dreamlifter,  built to carry disassembled wings and fuselages of 787 Dreamliners from the subcontractors in Italy and Japan to Boeing Field for final assembly.  It's even bigger in person!