Garfield Comic Strip Easter Egg - Calvin and Hobbes Cameo

In one comic strip (July 17, 1994), where Jon is locked outside by Garfield while exposing himself to the neighbothood wearing Bunnie Jammies, you can see a blond kid wearing a striped red T-shirt. That's Calvin from the Calvin and Hobbes comic strips, written by Bill Watterson. He's even holding the stuffed version of Hobbes.
Jim DAvis, creator of Garfield, stated that he loved the Calvin and Hobbes comic strips, so this may be a tribute to his favorite comic.