This is the only Garfield costume I could find online. Basically I made the jumpsuit out of orange material, and got some black cut to make the stripes, etc. Then, by using this picture and pictures of the actual cartoon on line, as a guide, I made all the details.
I hot-glued on all those stripes on the back. I cut out diamonds of the material, then cut those into strips.
Here is the picture of the Odie costume.