For those of you with pets, they are a boon and burden. Aside from their registered name, what nicknames do they go by?

My cat Socks:
Garbage Cat
Deadpurr
Bacon Thief
Fat Brat Cat
Princess

My cat Gemini:
Gem
Gem-Gem
Lady Meow-Meow
Spider-Cat
Her Imperial Brattiness

My older cat, Bacon, (whose name is pretty funny as I am a vegetarian) he has weak back legs from an illness he had as a newborn so as a result he walks weird. I call him "Wiggle" a lot, but more often "Squish" because he's pretty fat. Rasputin, the younger one, I call "Spoopy" because he's all black- I probably call him that more than his name. He is often addressed by (and responds to) "Turd" and "Stupid" because he has a generally dopey demeanor.

I don't have any animals that have nicknames, but my sisters cats have loads of nicknames:
Socks: "Socksy-Baby" (my baby sister calls her this), "Socks in a cardboard box", "Socksy", "Big sister"/"big boss" (Usually she's referred to this when talking to the other cats) - I'll have to start calling her "Fat Brat Cat" because that would suit her too
Izzy: "Iz-Iz"
Mittens: "Mit-Mit", "Tuxy" (being a tuxedo kitty - Socks also gets this sometimes, but she's blue/white, whereas Mittens is black/white), "Black and white and cute all over"
Amber: "Amber-cat", "Little Tantrum" (she's the tiniest of all the cats (Socks is 4ish, the other 3 are around 1 year old) but she will happily attack Socks despite the size difference) "Pretty eyes" (She has lovely orange eyes).

I have an over-abundance of nicknames for my animal companions. A lot of the time I use the same ones for different dogs (and in the past cats) - sausage, pudding, sweetheart and so on, but there are specific names for certain animals. Meg, my little sweetheart, was nearly always called Baby throughout her entire life. If it wasn't Baby it was Sweetpea. Don't know why really. Her companion dog, Harry, was called Harry The Dog. I know technically that's the same name but I used to sing to him and most of the time it was a song based on the Addams Family theme tune (60s version) and that was its first line:
https://www.youtube.com/watch?v=-3CH0tN515M
My version was also complete with wobbly rhymes. That's the programme that also got me interested in playing the harpsichord - something my harpsichord tutor at college heartily disapproved of when I told him. I think my interest was supposed to have originated in something more noble <tbbbbhhhhhhhhhhhhh>.

I call my cats Buddy and Terrence "Baboo" all the time. I also refer to them as "my good baby" lol

My animals are my furbabies. I currently have 1 dog (see avi) and 2 cats.

Dog is 2 years old and his name is Moose. His name comes from his size, he's 1/2 Boxer 1/2 Saint Bernard. He gets called Moosehead, Bonehead, Boy, Wigglebutt, and I think there are a few others I can't think of atm.

Cat one is 14 years old and her name is Bug. Her name comes from the fact that even as a kitten she talked and talked and talked. Her nicks are Ms. Bug, Bug a bug, or a combination of the two.

Cat two is 12 1/2 and her name is Nala. Her name stems from when I got here at a week old and was hand raising her she wasn't to steady on her feet and would roll on her side with her paws in the air ready to take on anything that came at her. (For those who don't know or don't remember, the the young lioness cub was named Nala.) She's my little (not so little anymore) lioness. Her nicks have grown in number in the past year do to her plumping up. They are Nals, Baby, Bratinela, Chunky Monkey, Rolly Polly, Pudge or Pudgebutt, and while I've not actually called her this she could double as Garfields twin.

When I was in my late teens, we had a beautiful black cat (who is now dearly departed and greatly missed). My sister gave him the very cliche name of Charcoal and nickname of "Charcky". Originality apparently not her strong suit.
I never really noticed because I am really used to my mom's Chinese-English accent, but I guess as the stereotype goes, she didn't really pronounce very well the "R" or "L" sounds, so my mom saying "Charcoal" sounded more like "Cha-ko". So one time at the vet, the people there apparently didn't know what my mom was saying and they put the cat's name down as "Chuckle".

I don't know why, but I thought that sounded funny and cute, so from then on, I called him Chuckle and imagining a cat chuckling made me chuckle. My friends called him Chuckle too, except one friend who called him Chuckles. My sister didn't care for that much. She's the easily irritated type and took it as an insult to the name she gave him. To me he was Chuckle for the next 15yrs up until I found out he'd died. Such a sweet cat, I miss him.

My first cat was Chaos but I tended to call her Cady (short for Chaos) or Blossomhead (teasing because she was delicate and cute like a blossom but very intelligent and mature but Blossomhead sounds like the opposite of intelligent).

My second cat was Modeen but was only ever called Modee, but she was also Motorhead, Momo or "my chicken".

Then my first chihuahua was Xena (she came with that name) so she was Xena Bombina, Xenee Bombini, my flying bombini, beanie or my little bean.

Then my second chihuahua was officially named Gabrielle (came with that name) but was always called Gabbi, Gab-Gab, Gabbadoo, Gabbasaurus, and after my second cat died she became "my chicken".

Now they're all dead and I just have a canary called BB (baby bird). Now she's my chicken but when I call her that it doesn't feel right!

One of the best pet nicknames was given to the late Maggie Simpson. Yes, that was her name. She was a beautiful, fluffy, tortoiseshell cat. When she was first brought into the family, she would open her mouth to meow but nothing would come out! Eventually, these meows of nothingness turned into peeps. She became known as Peeps-a-lot, or Miss Peeps.

My baby, Daisie, is a rather pathetic lump of fur rather than a real cat. I love her dearly. :lovestruc Her nicknames include:
-Crazy Daisie, Tubs, Weirdo, Baby, Sweetie, Daze
And my dad's favorite, "Miss Daisie." Essentially, she is my child.

As for our other two cats, Sheldon and Flynn, they go by:
-Shelly (She is indeed a female,) Shell, "Miss Sheldon" (guess who came up with that,) and Shelby.
-Mr. Flynn, Errol (He's named after Errol Flynn, a 20th century actor,) Fluffy, Princess, and my dad's colloquial "Little Buddy."

My lone gerbil, whose two brothers have dearly passed on, is named Franklin. However I occasionally call him Franks, or Frankles.