Bart, also known as Bartie, Bartiepupples, Bartholemew, Bartolomeu, Bartiepuppups, Buddy, Bud, Budlet, Buddy-Boy, Gitface, Stinky, Poohead and Baby (the last one by my partner rather than me).
I have a 9 year-old cat named Mongo. I named him after the character in Blazing Saddles because he was the meanest kitten in the litter. Anyway, he also responds to crackhead, dip sh**, buddy-boy, and dummy.
In addition to his regular name, my long-ago late dog was also called "Li'l Woofy" by me alone. As I'd approach I'd say "woofy-woof" and he'd try to mimic me.
Cat #1, name = Hoover
- called Hoover
Cat #2, name = Si (as in Siamese... guess what kind of cat he is)
- called Si or Stupid
Cat #3, name = Misty
- called Misty or Mistaywa
Cat #4, name = Ulysses
- called Ulysses (rarely), Useless, Uly, Utae-islae, bud, buddy, kitty, or cat.