I remember a movie where a bunch of kids/teens pick up a guy wandering around that turns out to be an unstoppable monster or alien. They all end up in a house where everyone is dispatched except one, blonde girl. The movie ends with another group of teens picking her up wandering around and she doesn’t speak. They get her into the vehicle where she just stares at them and then shrieks; turns out she is the monster suggesting that it killed her too and took her form.
The movie goes to credits after she shrieks and lunges at the camera. Early 2000s (2000-2016) maybe?