Personalized Santa Hat Brain Toddler Long Sleeve T-Shirt. A happy brain wearing a Santa hat is a humorous winter holiday gift design for psychologists, neuroscientist, neurologists, neurosurgeons and medical students. 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.