Four Main Food Groups - Funny Christmas Sweater style shirts and apparel. Great for Christmas parties, office parties or gift ideas. ShirtInvaders™ brand designs are created with our unique vision, style, and attitude. We want to impress everyone with our quality, our creativity, our speed and our motivation... From our customers and competitors to our own designers and printers. We’re not just a t-shirt shop, we are a unique brand with a hunger for success, a motivation to impress and a drive to set new industry standards.