Personalized 4th Birthday Monster Truck Toddler Long Sleeve T-Shirt. I'm Four! A red monster truck drives over the words. Great fourth birthday gift for your favorite 4 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.