While the strip in its early years resembles its later form, there are significant differences. The art was cleaner, sleeker, and simpler, with thicker lines and short, squat characters. For example, in these early strips, Charlie Brown's famous round head is closer to the shape of an American football or rugby football. Most of the kids were initially fairly round-headed. As another example, all the characters (except Charlie Brown) had their mouths longer and had smaller eyes when they looked sideways.