Personalized 4th Birthday Dinosaur 4 Year Old Toddler Long Sleeve T-Shirt. Cute dinosaur number 4 to celebrate a little boys 4th birthday party. 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.