Personalized I Believe In Santa 2 Toddler Long Sleeve T-Shirt. Funny Christmas Toddler Long Sleeve Tee - White with Santa cap says I BELIEVE IN SANTA... JUST BECLAUS. Perfect holiday gift for anyone who believes in Santa Claus and Christmas. 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.