Personalized Dinosaur 3rd Birthday Toddler Long Sleeve T-Shirt. Happy birthday! A cute dinosaur wearing a birthday hat peeks around a 3. Cute gift for the three year old's 3rd birthday! 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.