Personalized I'm Nine Years Old with Dog and Mouse with White Text Infant Tutu Bodysuit. 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 Nine Years Old with Dog and Mouse Infant Tutu Bodysuit - Black, perfect for young readers, helpers, and great friends on their birthday. Tutus are all the rage! This one is made of matching tulle and stitched right into a soft creeper.