The only thing I remember is that the MC turned into a cat and became the cat of the FL (?) I think it is a CN and I seen the translated version here. You can recommend me anything you know cause I can't really remember because I have only read the synopsis.
Do you remember which country that novel from? CN, JP, KR, etc. Is it translated version or MTL/raw? CN GL has plenty of novels that have similar synopsis; more details may help other figures it out.
Possibly Villainess With a Cat Changing System? Or Becoming a Movie Queen After Transmigrating as the Villain's Cat?