If you follow the LOLcat photoblog I Can Has Cheezburger.com, you'll recognize the phrase "basement cat." In the lexicon of LOLcats, "basement cat" is the Devil — a black cat with burning red eyes and fangs.
The LOLcats also have "ceiling cat" — an angelic white cat that is often shown at the very top of the set of stairs or on a tall bookcase.
Ironically, Mabel, our "basement cat," is a black cat. And Sheba, who likes to be in the highest place in the house, is a white cat.
Today, basement cat and ceiling cat met briefly in my office. Sheba was completely relaxed. She looked at Mabel, and went back to purring. Mabel, clearly traumatized by her recent persecution, gave a sharp hiss. But since Sheba couldn't hear it, there wasn't a problem.
Mabel soon calmed down, and was disappointed when she was taken back down stairs to her den.