Personalized That's right! You're my best friend! Long Sleeve T-Shirt. Show off your bestie with That's right! You're my best friend! Long Sleeve T-Shirt - Athletic Heather, featuring Dog and Mouse from the children's book "Dog and Mouse" by Michelle Nelson-Schmidt. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL