Personalized Dog and Mouse Best Friends T-Shirt. Friends are always there for you - rain or shine. Dog and Mouse Best Friends T-Shirt - Pacific Blue features two scenes of this budding friendship from "Dog and Mouse" by Michelle Nelson-Schmidt. Everyone loves our Custom T-Shirts! Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.