I'm going to link you to a YTMND video displaying six strips that ran the week before Halloween in 1989. I would just link to the Garfield archives and embed them in the post, but the archives have apparently been colorized, and the mini-series is much more profound and effective in black and white.
So go watch Garfield is Dead and then come on back here.
Spooky, right? As you saw in the video, the series is even addressed on the Wikipedia page for Garfield.
Here's what freaks me out: there's no "it was all a dream" ending. There's no ending at all. Garfield is shown to force himself into a state of denial that brings Jon and Odie back to him, and the final word panel begins with the phrase "An imagination is a powerful tool." This is no cautionary tale, and no nightmare. Garfield never woke up from his bleak, lonely world, he simply refused to accept it, and forced himself into perceiving that Jon and Odie were with him. Canonically, there has been no retraction or resolution.
In other words, for the last 19 years, the Garfield strip has been a fevered, desperate delusion, dreamt up by the eponymous main character to stave off his crushing loneliness. As he has apparently eaten no real food in that time, the only sensible conclusion is that Garfield the cat died sometime in October, 1989, and his ghost, unable to move on from his home but unable to deal with its emptiness, has imagined life continuing as-usual because the alternative is too hard to accept.
That puts a rather bleak and heart-wrenching spin on the whole thing, and creates a fascinating counterpoint to my complaint yesterday that "it's the same strip over and over". If the events of the strip are figments of Garfield's (limited) imagination, it would make sense that he should return to the same occurrences and ideas over and over again. It's all he's got. It's what comforts him.
Now, the actual answer is far more mundane. Apparently Jim Davis "laughed loudly" when someone mentioned these strips and the "Death of Garfield" speculation that they spawned. He stated that Garfield is not dead, and that:
It was simply a week before Halloween and Jim wanted to do something legitimately scary, as opposed to Halloween-scary. "Ghosts aren't scary..." he told me before explaining that before writing the strips he went around to everyone he knew and asked them what truly scared them. The answer he got most often was "being alone" or "dying alone". Just that simple.1
So, of course, it was never meant to count as Garfield canon. Incidentally, Garfield's repetition and lack of inspiration is actually due to the fact that, apparently, Jim Davis is not the guy who draws the strip daily. He's too busy managing the Garfield business, and has hired a team of artists who do the strip for him. The Wiki page claims that he still writes and sketches each strip, leaving only the finishing work to the team, but I'm going to guess that most of the time he just lets them slap something together and signs his name on it.
But in the last two days I've discovered three disparate and very intriguing new ways to interpret the Garfield daily strip. And I prefer any one of them to "I'll license anything you put in front of me."