I've had a lot of pets, haha. Sometimes I adopt and just stick with the random name they were given, but here's some I actually named myself.
I made a sim that was kind of a mash up of me and my best friend, and I gave her a cat that was a mashup of our childhood pets (we both had orange tabbys). Mine had been named Marmalade and her's was Milo, so I named this little guy Marlo :-D
https://i.imgur.com/RcKWSUB.png
That sim eventually married Catarina Lynx, lol, but by that time Marlo and all of Catarina's cats had passed away, so as a "wedding" gift I got them each a new kitten. I adopted from in game, picked two kinda random, and was gonna just keep the names they came with but then I saw them together and...
https://i.imgur.com/iVMeYBS.png
omgosh I just couldn't resist--I called them Dagny and Laila (Day and Night), haha.
Later, when they had kids, I got two puppies too, and keeping with the theme, named them Danika and Vesper (Morning and Evening)
https://i.imgur.com/xWbtJkM.png
In another save, I had a game of thrones inspired thing going, and I got one of my sims (Wolf Stark) a white fox named Winter, than another dog (can't remember the breed) to mate with and named it Fall (get it...Winter...Fall...). They had puppies that I named after months--December, January, February, November, that kinda thing. Here's Wolf, Winter, Fall, with January and December as puppies.
https://i.imgur.com/33rzJgb.png
In a another household a sim with the friends to the animals aspiration wanted to adopt a cat and then a dog. The cat came with the name Bo but I changed it to Beau since he's a spoiled little thing, and then the puppy I named Blanche to match.
https://i.imgur.com/cdqaaYF.png