I had a very vocal Siamese cat named Milo, whose name was changed to Meowme by my niece after I told him “Don’t meow me!” because he was having a meowing fit.
A cat started breaking into our house to sleep on beds when he thought no one was looking. He is gray. We called him Gray-Cat-You're-Not-Our-Cat.
This lasted months.
He's now just Grayson, 'cause he absolutely is our cat now.
(Took some coaxing to get him used to people but he never looked back)
My first dog came with the name "Seven" as she was the 7th puppy born of the litter. Due to my mom watching a lot of "Seventh Heaven" at the time, the name morphed over time to be "Heaven."
this really is how it happens sometimes, I love it.
My parents "temporarily" took in a stray white cat and within a few weeks it was our beloved WC, short for White Cat of course.