All of my cats have their weird idiosyncrasies. None is harmful. Most are amusing.
Gracie grunts. It’s a bowel movement grunt but there is no poop. She does it when you pick her up or when she eats. Other times too. It’s a “Gracie” version of purring. She does the traditional purr too.
Morgan loves the sun spots. She’s a large and lanky cat and will do what she needs to try to get all of herself in the sun spot. (It’s like an overly large cat trying to fit in a small box.) The best was when I was raising plants under a heat lamp for my garden. She moved them to the side and took a nap under it.
Mollie loves watches. Whenever she can, she will rub her face on my watch. Any watch. Perhaps she’s trying to mark it with her scent but it’s crazy to watch (no pun intended).
Hazel has the food obsession. She can be elsewhere in the house, even on a different floor but she hears a cat food can pop or a lid open. She can even hear the soft opening of the dry food container. I secretly suspect she had cameras installed to watch all the food spots.