Personalized T-Rex Balloon Birthday Toddler Long Sleeve T-Shirt. A cute T-Rex dinosaur wearing a birthday hat has a balloon tied to its tail. It is singing and playing the guitar, wishing you a happy 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.