Personalized Dog and Mouse- Best Friends Toddler Long Sleeve T-Shirt. Show off your bestie with Dog and Mouse- Best Friends Toddler Long Sleeve Tee - Red, from the children's book "Dog and Mouse" by Michelle Nelson-Schmidt. A classic for Fall, Winter and Spring, these long sleeve toddler t-shirts are sure to be a staple in your child's wardrobe. Whether layered or alone, this t-shirt is soft yet durable enough to stand up to your toddler's playtime demands.