Personalized Triangle Egghead Youth T-Shirt. An egghead with a triangle is a cute musical design for percussion musicians, students and teachers at back to school, marching band season, birthdays, holidays and graduation. 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.