Personalized Unicorn Christmas T-Shirt. Unicorn Christmas - A cute little unicorn wearing a Santa hat uses some unicorn magic to make a sparkling Christmas tree with rainbow decorations. Everyone loves our Custom T-Shirts! Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.