The serigala, wolf that stopped Emma from leaving Storybrooke has not been telah diberi an identity, but we have been telah diberi clues enough to determine it. In a sneak peek for tonight's episode,Graham is often featured with one serigala, wolf as his companion. In another sneek peak,the Evil Queen later reveals that he was raised sejak wolves. Since everyone in the fairy tale land was affected sejak the curse,even animals, I believe that the serigala, wolf that kept Emma from leaving is the same serigala, wolf that was Graham's ally and that possibly raised him.
