In fact cats are mentioned in the bible, in the deuterocanonical book of Baruch 6:21 (6:22 in some versions). This was part of the bible up until the reformation and is still part of the bible for catholics and orthodox, but protestants consider it apocryphal.
Yes, I guess it's obvious I'm not Catholic, because I didn't know of this book.
Having said that, the verse says cats fly like birds. I have a strong feeling that, like unicorns, they mean a different animal that they happened to call "cat" or (mis)translated the original word as such.
I think the award for the most theologically significant word not in the KJV (or any other English translation, for that matter) is "trinity".