Personalized Mermaid Tail 1st Birthday Newborn Layette. Cute 1st birthday Newborn Layette - White with splashing mermaid tail, seashells and starfish says This Mermaid Is One. 100% combed ringspun cotton 5.8 ounce 1×1 baby rib sleeper. 3/8" flatlock binding at envelope neck and cuffs. Back sleeve flap to protect hands. Elastic opening at bottom. Infant: 0-3 Months