Personalized I'm Four Years Old with Dog and Mouse Women's Plus Size T-Shirt. Celebrate your birthday with Dog and Mouse, the unlikely best friends from the children's book "Dog and Mouse" by Michelle Nelson-Schmidt. I'm Four Years Old with Dog and Mouse Women's Plus Size T-Shirt - Heather and Hot Pink, perfect for young readers, helpers, and great friends on their birthday. 100% combed ringspun cotton premium jersey (CVC Colors are 60/40 combed ringspun cotton/polyester)