Personalized Happy Birthday Train T-Shirt. Happy Birthday! A cute choo-choo train filled with adorable animals chugs along the tracks bringing lots of birthday gifts! 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.