Personalized Math Teacher Zombie Fighter Youth T-Shirt. Math Teacher I fight zombies in my spare time is a funny gift design for math teaching gamers at back to school, birthdays and holidays. 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.