Thanks for all the guesses on what BJ stands for. Kea was correct as the very first comment. BJ stands for Betty Jane. There was, of course, a mix up about gender. BJ was named after DP's grandmother, who was an avid cat lover and rescuer of strays. To read more about BJ click here.
And now may I present to you our King and Queen, Wizard and Penny. These two rule the roost jointly, most plutonically and without squabble. They're not snuggly with each other, though Penny is snuggly with Nick, Angus and Owen. I've mentioned before that Penny does not like Snafu, however Wizard seems to like him a lot and will tussle with him lightly (but not long enough to qualify as a Friday Night Fight).
I think they have a perfect partnership, and when it comes down to it, Wizard defers to Penny.