Personalized Herpetology Is Ribbiting Newborn Layette. Herpetology is ribbiting text with the word ribbiting replacing the word riveting and a happy frog is a funny gift design for scientists, teachers and school students engrossed in the study of amphibians. 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