In 1976, Jon started in The Pendleton Times. Garfield first appeared very fat and had a small mouth. He looked more hairy and had more notable whiskers. He got less hairy through the 1970s and by 1978, he looked more like a cat. As he got older, through 1978, Garfield's head and eyes became bigger, allowing him to look much more cartoony. His feet evolved as well.
By the mid 1990s, Garfield and most other animals somehow learned to be bipedal.
Jon Arbuckle originally had 5 fingers. From early to mid 1976, Jon had a circle-like nose and no line under it. By late 1976, Jon gained said line under his nose.