Garfield

Garfield (not to be confused with a U.S. President) is a comic strip made by one Jim Davis in 1978. It is one of the most famous comic strips of all time, though nowadays it's more infamous for being horribly stale and bland.

In case you've somehow never heard of the series, the title character is a fat, lazy orange cat, and the comic is all about him and a variety of supporting characters, the most well-known including his owner Jon, whose inability to attract women and various "loser" aspects drive a good portion of the strip's humor, Odie, the stereotypical dumb dog for Garfield to beat up on, Nermal, the self-proclaimed "world's cutest kitten" who bugs Garfield incessantly, Liz, a veterinarian who eventually hooked up with Jon (don't ask why, just roll with it), and Arlene, who is ostensibly Garfield'd girlfriend but doesn't show up all that often.

Being a merchandising empire, practically everyone has heard of the series. Two men, much more devoted to the series than most, decided that they should write fanfiction for it. Those men, as you could guess, are the twosome who created The Calvinverse.

This list of references also includes the animated spinoff Garfield and Friends, often considered much better than the original series due to having a rather different style of writing, and the various animated special produced during the 80's.

References in the Calvinverse

 * In Can You Imagine That?, Tracer Bullet asks "What do you know about the Klopman Diamond?" - the Klopman Diamond was a running gag on Garfield and Friends. He also asks "IS PROFESIONAL [sic] WRESTLING FIXED?", a direct quote from the episode "All About Odie". (For context, the premise is that Garfield is hosting a lecture on Odie. At one point, he asks "Any questions?," upon which an audience member says the line. He then clarifies if there are any intelligent questions.)
 * Garfield is among several names listed in one sequence in the original Calvin and Hobbes: The Movie
 * One bit in Chapter 3 of Calvin and Hobbes Get XTREME! directly quotes from this Garfield strip (involving Jon running over a cow, which Calvin's dad does in XTREME!). Also, Chapter 6 turns into a crossover with the strip apropos of nothing.
 * The entire premise of Attack of the Teacher Creature is directly taken from the children's chapter book Garfield and the Teacher Creature. Seriously, even specific lines are taken from the beginning (if you dare to look inside).
 * Calvin and Hobbes: The Series reference the series a lot, particularly in early episodes.
 * The opening begins as a homage to the intro of Garfield and Friends. In the original, Garfield tap-dances on the fence to a record player while a narrator says "Ladies and gentlemen, Garfield and Friends!" He then lightly taps the record player, starting the theme song (and thus, the introduction proper). This exact sequence is copied for The Series, only the record player is now a CD player (no relation to The MTM).
 * Several episodes namedrop Garfield and Friends.
 * "The Black Turning Funnel Part 1" takes a gag directly from this strip (Jon is Calvin's mother and Garfield is Calvin himself).
 * "A Calvin and Hobbes Christmas!": During Calvin's rewritten version of "The 12 Days of Christmas", the line "FIVE BILLION PRESENTS!" is a direct quote from the official site's "12 Days of Christmas" feature (it only shows up during Christmas, though, so good luck finding it anywhere in April).
 * When Hobbes turns on the radio to dispel his depression in "Tonsil Terror", the radio plays "So Long, Old Friend", from the animated special Here Comes Garfield. At the end, when he and Calvin reunite, the radio plays "Together Again" from the same special.
 * Dad quote this strip when he begins his mid-life crisis in "Gasping for Air".
 * Socrates' sleep-talking in "It Will Build Character" includes the cast of the comic.
 * Jack remarks "I wonder if Charlie Brown could use a robot?" in "The Alien Huntress", a slightly-altered quote from this strip. Sadly, the ramifications of Charlie Brown owning a (potentially) killer robot are never explored.
 * The beginning of "Dad" has the titular duo watching Garfield and Friends.