From my Wikipedia bio:
'Bill the Cat, or Bill D. Cat, according to the final Outland strip, is a fictional cat appearing in the works of cartoonist Berkeley Breathed, beginning with the comic strip Bloom County in the 1980s and continuing in Outland and Opus in the following decades. Bill also appeared in some of Breathed's illustrated children's books . . . . . . .Breathed has also described Bill as his attempt to create a character so repulsive that it would have absolutely no merchandising potential."