Cats don’t always make the best dogs
I’m almost positive this is a cat with cerebellar hypoplasia. It’s not as scary as it sounds – it’s a congenital thing cats get when the mom cat is pregnant and has panleukopenia at the same time. They have no sense of balance and it can range from slight wobbling around while walking to acting like they’re so drunk they can’t stand. So the exact opposite of that stereotype that cats are so graceful that they always land on their feet.
It’s permanent from birth but it doesn’t get any worse, and the cats honestly have no idea that life should be any different and are perfectly happy! You just need some special setups in the home for food/water so they don’t faceplant and inhale anything, and make sure they can’t get up onto places that it would be hazardous to fall from.