Personalized Submarine 5th Birthday Toddler Long Sleeve T-Shirt. THINGS ARE LOOKING UP 5th birthday Toddler Long Sleeve Tee - White with big number 5, colorful submarine, little deep sea explorer in the porthole and bright fish with bubbles. 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.