Adorable but runs a little big. I purchased size medium for my 11 month son who is in 12-18 month clothes. The costume is pretty big on him but not to the point I would go through the hassle of exchanging. My daughter wants to be little red riding hood for Halloween so I thought it would be fitting for my son to be a wolf. I looked at several different costumes and this by far was the best quality and at the best price.