This shirt reads Know Your Enemies, and it features the evil characters that Mario and Luigi have faced in the Super Mario Bros. video game series. The shirt shows Goomba, Koopa Troopa, Koopa Paratroopa, Piranha Plant, Blooper, Cheep Cheep, Spiny, Bullet Bill, Lakitu, Hammer Bro, Buzzy Beetle and Bowser. You'll have fans of Super Mario Bros. saying "Mama Mia!" when they see you in this Mario Enemies t-shirt.