Personalized 4th Birthday Unicorn Youth T-Shirt. A pink unicorn surrounded by a colorful rainbow, next to a sunny yellow 4. Cute gift for the birthday girl's 4th bday! 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.