Classic comic strip from the '80s (1980-1989), created by BerkeleyBreathed? (http://www.berkeleybreathed.com). Featured a host of both human and (speaking) animal characters, including OpusThePenguin? and BillTheCat?.
Did BillTheCat? actually speak, or just make noises in response to others' speech?
Typically, BillTheCat? is in a religious trance/tequila coma, and responds "Ack!" to almost all stimuli (e.g., when hit with baseball bat during presidential debate practice). Every so often, BillTheCat? will have moments of lucidity and rattle off a coherent sentence or two, pre-dating SilentBob? by a decade: "Say, you don't suppose a Jury Box is anything like a Litter Box?", asks BillTheCat?, during his trial for treason and conspiring with the USSR. His lawyer, the ever-slimy SteveDallas?, replies, "Shut up, I don't talk to Communists."
BloomCounty was a daily strip, discontinued when Breathed decided he didn't want to (or didn't have the creative juices for) continue meeting daily deadlines. There have been two Sunday-only spinoffs of Bloom County--Outland, which ran from 1989 through 1993/5 (can't remember, have seen different sources for both dates), and Opus, which just started its run last month (November, 2003).
So far, I've been a bit disappointed with Opus. It already contains one major RetCon--the presence of our favorite penguin's mother--and Opus stuck in Antarctica isn't as funny. But I haven't written it off yet...--ScottJohnson