Personalized T-Rex 1st Birthday Toddler Long Sleeve T-Shirt. A cute little T-Rex dinosaur is smiling and wearing a birthday hat as it sits with its 1st birthday cake. Adorable gift for your one year old! 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.