Napoleon's nicknames are: Napoleono (original, I know :P ), Fatarse (he gained a lot of weight recently), Bad Cat (used to be Good Cat.)
Josephine's nicknames are: Jo, Jojo, Jojojo, Jojobaby (sensing a pattern?), Good Cat (used to be Bad Cat.)
Nan (my parents' dog's) nicknames: Nanoo, Twit, The Phantom Sh***er (as she likes to leave 'presents' when no one is looking) and lately, Jay Are/JR (she's a Bichon Frise who was recently shaved, so she looked like an albino Jack Russel Terrier.)
To explain the Good Cat/Bad Cat: When Jo arrived, she was hissy and mean and surly, and Napoleon was our friendly but meddlesome cat. They were called Bad Cat and Good Cat (respectively.) Since, Jo has become sweet and easy-going, while Napoleon has gotten a little more meddling and troublesome. Hence the switch.