Personalized Coolest Engineer Toddler Long Sleeve T-Shirt. A snowman wearing a hard hat with text The world's coolest engineer is a humorous engineering design. Fun gifts for college students and engineers for birthdays and the winter holidays. 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.