Personalized Choo Choo Future Big Brother Youth T-Shirt. Future big brother Youth T-Shirt - Kelly Green with a colorful choo choo train on it's tracks. Message says I'M GOING TO BE A BIG BROTHER. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.