Personalized My First Boo T-Shirt. 1st Halloween T-Shirt - Pacific Blue with a cute little smiling ghost with rosy cheeks, a big yellow moon and little smiling bats. He says MY VERY FIRST BOO! 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.