Garfield

In the 1970s, Davis authored a strip, Gnorm Gnat; it met with mostly negative reviews. One editor said that "[his] art [was] good, [his] gags [were] great", but "nobody can identify with bugs". Davis took his advice and created a new strip with a cat as its main character. The strip originally consisted of four main characters. Garfield, the titular character, was based on the cats Davis was around growing up; he took his name and personality from Davis's grandfather James A. Garfield Davis, who was, in Davis's words, "a large cantankerous man". Jon Arbuckle came from a coffee commercial from the 1950s, and Odie came from a radio advertisement Davis had written for Oldsmobile-Cadillac. The fourth character, Lyman, was Odie's original owner; he was written in to give Jon someone to talk with. Davis later realized that Garfield and Jon could "communicate nonverbally", and Lyman was written out. The strip was originally rejected by King Features Syndicate and Chicago Tribune-New York News; United Feature Syndicate, however, accepted it in 1978. It debuted in forty-one newspapers on June 19 of that year. In 1994, Davis' company, Paws, Inc., purchased all rights to the strips from 1978-1993 from United Feature. The strip is currently distributed by Universal Press Syndicate, however, rights for the strip remain with Paws.

Garfield quickly became a commercial success. In 1978, less than three years after its release, the strip appeared in 850 newspapers and accumulated over $15 million in merchandise. To manage the merchandise, Davis founded Paws, Inc. By 2002, Garfield became the world's most syndicated strip, appearing in 2570 newspapers with 263 million readers worldwide; by 2004, Garfield appeared in nearly 2600 newspapers and sold from $750 million to $1 billion worth of merchandise in 111 countries.

As it progressed, the strip underwent stylistic changes. The appearance of Garfield was probably the most notable; he underwent a "Darwinian evolution" in which he began walking on his hind legs, "slimmed down", and "stopped looking [...] through squinty little eyes". His evolution, according to Davis, was to make it easier to "push Odie off the table" or "reach for a piece of pie".

Davis is no longer the sole artist of Garfield. Though he still creates the stories and rough sketches, other artists handle the inking, coloring, and lettering; Davis spends most of his time managing the business and merchandising of Garfield.