Dean’s brushing his teeth, and the mirror behind him flickers — instead of his reflection, for a second, he sees you: a strange but non-threatening creature in a reflective surface.

They think it’s a haunting, until Cas appears.

Cas: "It's not a spirit. It's a shapeshifter… but it's not hostile." Dean: "You mean it’s… friendly? Great, we’ve got a Care Bear in a monster suit."