Heathcliff is a single panel newspaper comic strip, created by George Gately, which was rather popular during the 1970s. It features the adventures of the eponymous cat, Heathcliff, who is usually getting into some sort legal or extralegal hassles, due to his gluttony and aggression. Despite his disregard for convention, Heathcliff usually outwits the various forces trying to keep him from fish, birds, fame, females, or whatever else he is impulsively chasing down. This is all cheered on by the reader, because Heathcliff is a cat, and cats get away with things. A cat beating up a dog is much funnier than vice-versa.
Apparently, the strip is still in production, in which case I assume that it has gone the way of all long-running comic strips. I know it mostly from the paperback collections from the strip's height of popularity, and I have to say that I find the strip charming and entertaining. For a single panel strip, the comic displays action and timing, and something like narrative tension. Within the limited repertoire of activities that Heathcliff does--fighting dogs, tipping over garbage cans, and tripping up the milk man-- I actually find the iterations on the theme to be surprising enough to be worth reading. I also find Heathcliff sympathetic enough, in his rough hewn glory, that the vicarious thrill of rooting for his success in his misadventures lifts my heart just a little.
Also, when the competition for single panel glory is Marmaduke, Dennis the Menace and The Family Circus, being a standout is not too difficult.