Some people have pointed out that the context (we think) is that the girls had been (perhaps) making fun of another girl who says she is a cat.
I've been teaching for over ten years, and although no one has said they are a cat, I have dealt with kids making fun of other kids more times than I can count. It is a standard thing to deal with. I've never had to call anyone despicable.
You keep them behind after the lesson, have the standard calm conversation about code of conduct. You don't tell kids what they should think, only how they should behave.
"It doesn't matter what you think about Catgirl. You need to keep your views to yourself around her. I will be monitoring your behaviour over the next few days and we will discuss this again if I find you're continuing to be hurtful to classmates." Job done, they can feel free to put me on tiktok. It's really not hard. No need to engage on the ideology or try to change their views.