Personalized Radioactive Tree Circle Toddler Long Sleeve T-Shirt. A tree made of radioactive symbols with a red and yellow glow in a colorful circle is a humorous Christmas design. Fun holiday gifts for college students, physicists, nuclear engineers and workers. 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.