Personalized 1st Birthday Monster Infant Romper. 1st birthday monster Infant Romper - Raspberry. A cute monster holds a bright yellow balloon to celebrate the one year old's first birthday! Great gift for your little monster! Meet your new favorite outfit! Keep dressing simple with this one piece, lap shoulder t-romper. Super soft and perfect for baby's sensitive skin. 5.5 oz. 100% combed ringspun cotton premium jersey (CVC Colors are 60/40; Heather is 90/10 combed ringspun cotton/polyester)