She's just nasty. In the books, she ruined Jurassic Park, and now she's out to try and ruin the universe; Thomas
Dark Velocity is the big raptor "Queen" hailing from the world of Isla Nublar. The T Rex killed her ,but Kronos has brought her back.
She has the power of darkness, and impressive speed. Her claws and intelligence are lethal. She is one of the original concepts, alongside Tonto's squirel minions. She was shown to have attacked Rose Weasly, but was immobolized by her magic.