Personalized Mouse Toddler Long Sleeve T-Shirt. A great finder, a great helper, and a great friend. Mouse Toddler Long Sleeve Tee - White from "Dog and Mouse" by Michelle Nelson-Schmidt wants to help, not because she has to, but because she wants to. 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.