Stewie (very fluffy black, greedy cat, can be a bit ditsy): Stewpot, Fluffles, Fluffy Rat, Stinky, Piggy, Mischief, Stew-pid, Pignatious (no idea, my dad came up with it and even he doesn't have a clue where he got the "natious" bit from), Clumsy
Smudge (tuxedo cat, very intelligent, often compared to a killer whale) Mudge-mudge, Smudgey, Keiko, Shamu, Einstein, Hitler (he has a moustache)
Rosie (one of my old cats who died about seven years ago- VERY naughty, tiny black English short-hair!) Gremlin, Rosie-Posie, Fish Breath, Silly Girl, Little Devil, Happy One, Daddy's Girl. And you used to hear my mum say "Oh, Rosie you little s***!" in the background at least once a month, so she affectionately became "little s***" as well!
Teazle (Rosie's twin, we lost her about six months after Rosie. Very quiet cat, could be grumpy. Cost us a lot in vet bills as she had a few health issues but was worth every little penny) Weasel, Old Girl, Weasel Woo, Grouchy, Mummy's Girl, Pig, Sweetie Pie