Evidently, Heathcliff predated Garfield by about five years. This would lead one to make the accusation that Jim Davis owes some creative royalties. However, as Joe has pointed out, Jim Davis is not a talentless hack, because Garfield‘s innovation was that he thought, while Heathcliff spoke. Hence, the subtle genius of Davis, and the archaic barbarity of George Gatley.
Interestingly, in the Heathcliff and Dingbat cartoon, there was a pumpkin named Nobody. We decided not to carve a jack-o-lantern of Nobody, because a pumpkin carved like a pumpkin is “as stupid as a bowl of mice.”
“Stupid as a bowl of mice” courtesy of Tracy Morgan.