Personalized St. Patrick's Day Rocks Youth T-Shirt. St Patrick's Day Rocks text with three dancing rocks holding shamrocks is a humorous Irish design for St. Paddy's Day. 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.