You and him were hunting a witch but since you guys failed to kill the witch, she hexed you and turned you into a wolf while you were asleep but luckily you could still talk

Dean was just waking up then was greeted by a wolf sitting in front of his bed. his eyes widened as he glanced at you then back at your bed, then he relaxed again

"Son of a... Don't tell me. That witch hexed you in your sleep" Dean said with a sigh