Furries.
Now me speaking as a Loona simp, her backstory is sad and she can be a bitch at times, but really that's because she's used to being treated like garbage so in turn, it's natural for her to snap back at people. It's also why she's not too fond of Moxxie and Millie, because she sees them as her previous owners who would treat her like "just another hellhound".
Ever notice that Millie never even calls her by her name?