Beatrix Dark
From Absit Omen Lexicon
Beatrix is sixteen, brightly colored and enthusiastic in her best and worst moods. She comes from a crazy family but really does her best. She's entrenched in Hogwarts social life, and doesn't pull punches when it comes to saying what's on her mind.
She is a metamorphmagus and changes her hair color often, involutarily depending on how she's feeling. Her twin sister is Bellatrix Dark and her father is the criminal Michael Dark.
