Opalescence is a white cat who wears a purple bow on her head. She also wears a purple collar that is studded with opals.
Opalescence is mean to everyone (even Rarity) except Fluttershy. Opal also has a bit of a sarcastic sense of humor, in one episode she is seen chopping off some of Sweetie Belle's hair, and she offers a smug look afterwards. Sweetie Belle suggested that she might be good with animals too, which was wrong.
Lives with Rarity