He used to be a fat orange cat with back stripes. When he turned evil he turned into a shadow of himself.
While he was good, he was simply lazy with only an interest of eating and bullying Odie. Now he is critically insane...
Garfield was once good, but when they caused the betrayal of '90 and got a kid to stop doing drugs, he became a tyrant with a corrupted heart and enslaved his former friends, causing mistrust among the clans.