Personalized Monster Truck 3rd Birthday Adult Sweatshirt. I'm Three! A red monster truck drives over the words. Great third birthday gift for your 3 year old who loves trucks. Stay warm and stylish with this classic adult sweatshirt, perfect for everyday comfort. Crafted from soft, durable fabric, it features a relaxed fit for added coziness. Whether you’re lounging at home, running errands, or enjoying outdoor activities, this versatile sweatshirt is a wardrobe essential for any season.