Onesies (a one-piece close-fitting lightweight garment worn by a young child, usually having sleeves but leaving the legs uncovered and fastening with press studs at the crotch.) The image below shows how onesies looks like:

Singer John Legend and his beautiful wife Chrissy Teigen dressed up in Onesies. Chrissy is wearing a KFC onesie. The proud parents of 9 month old Luna also shared lovely photos of their daughter, Luna. John Legend captioned the photo above: “Deep fried Pajama Jammy Jam”.