Wayne, my Biddy came in from outside and I feared that we'd have big territorial fighting. We has our share of posturing and our spats, but nothing too serious to worry about. Otis is your newest and I always have found that the new guy "has the most to lose" (in the heirarchy) and they usually put up the biggest fuss. I would probably have Otis be one of the last ones to introduce to Sunny. Try introducing Sunny to a more docile "couldn't care less" kind of cat.