Personalized Happy Birthday with Dog and Mouse Long Sleeve Creeper. Dog and Mouse are excited to wish you the happiest of birthdays! Happy Birthday with Dog and Mouse Long Sleeve Creeper - Heather, perfect for those who love this friendly duo from "Dog and Mouse" by Michelle Nelson-Schmidt. For chillier weather, dress baby in this soft long sleeve creeper in a great fitting 1x1 baby rib. 5.0 oz., 100% combed ringspun cotton, 1x1 baby rib. White is sewn with 100% cotton thread, Flatlock seams, Double-needle stitched rib binding on neck, shoulders, sleeves and leg openings,Reinforced three-snap closure on binding.