Personalized Pegasus Pony 4th Birthday Youth T-Shirt. A cute little pegasus pony with a pink mane and wearing pearls helps celebrate your 4 year old's fourth birthday! 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.