Knucklehead, goofball, putz, nimnode, luvins, imp. All said with great affection!?

Mattie- Mattster, Mattielion, Mats, Mattster the Cattster, Mattie Cattie, Mattieboo, Mattie Dorkface, silly dork, baby cat... Each name has a song to go with it.

Zippy, Zippity do dah, Dippy, Dipsy doodle, Little Asshole, Fuzzball, Zipster, Speedy, Monkeyface, Rat, Lovey, Snippy, Fleabag, Baby, Baby Zip, Zippy Baby, Zipper.

Razmataz, Fluff- fluff, Fuzz Butt, Monkey Face, Fluff-N-Stuff, Snuggle Face, Hair Monger, Shed Meister, Asshole, Jerk Face, Darkness-My Old Friend, Heathcliff (elongated form of his name, which is only Heath), Heathy Heath and the Fuzzy Bunch, Zuul, Vinz Clortho, Space Heater, Sir This Belongs On The Floor III, Crackhead, and their actual names, of course.

Big girl. Sweet girl. Bunny girl.

Ollie Bear. Munch-a-bunch.

And so on....

I have no pets...

I call my cat Boo Boo Bear...lol.

Let me think here:
Mazie is sometimes Z, Mazie girl, Mazer, Mazeroni, or (don't judge) Mazeroni and Cheese.

Lucky is sometimes Key, Kiki, Lucky girl, Baby girl, Pretty girl, or Beebee.

My newest, Munchie hasn't earned as many, but may I call him Munch, Munch boy, Munchie boy, or Munch man. He probably also thinks that his name is "Stop it!", "Get out of there!", "Leave her alone!" or "Goddamnit!" ?

So many furbabies, so many choices. I use their full names, versions of their names, evolved versions of their names (eg Einstien>Steiner>Steiny) or terms of endearment, which can be tricky since "honey" gets applied to any particular pet, causing potential confusion.

Typically I use some adjective that describes them somehow... Zip, Zippy, Mooch, sometimes Stinky Butt. But always said with love and affection.
I call all animals (and some kids... especially if I don't know their name) Boo-boo or Buddy, or some derivative there off. Cute Little Boo-boo, Sweet Buddy-boo, Boo-boo Buddy. Goofy/Stinky Boo-boo.
I don't know how I got into that, but it's always meant with kindness, no matter how unflattering the adjective.

Shit Head!!!!

As Terry Pratchett once wrote, all cats believe their name is "Yarghgetoutofityoubastard"!

(Probably misquoted, as I can't find it online)

That would be what they believe their human name to be, anyway. I'm pretty sure they have their own cat names... probably things like "Evilor, Flayer Of Souls" and suchlike.

Dorian sometimes gets shortened to Dory or just plain Asshole
Bianca is either Baby B or just B
Ginger is sometimes called Ging or Mr Bean Toes (not sure why my roomate calls him that)

Fluffernutter. Mr Fluffypants. Monsieur le Pantaloons.

Actual name? Heath.
There's more but he'd hurt me if I put them in print!

My dog Skipper has over 21 knick names. From Wippety WooWoo, to Old Brown Shoe, Joseph, Whip... It goes on. As a group, the pets are called "The Idiots"

You need an "All of the above" option for our household. Some of our options include Mingaroo, Muffaroo and Earl of the Girls.

I sometimes refer to them as my "furbabies" or my "familiars" .... the latter I use only with people who are "in the know" .... "familiars" is the word the Spanish Inquisition gave to cats owned by women who got accused of witchcraft.