Personalized Seahorse Aquarium Retro Toddler Long Sleeve T-Shirt. Cute seahorse silhouette on retro sunset background for a trip to the beach or the aquarium. 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.