I'm actually pretty sure it's the same Wolf that we saw in 1x07, I think it's the Huntsman's Wolf. It hasn't been confirmed yet or anything but, I think the wolf knew who she was and specifically prevented her from leaving that night. Plus how ironic the next place she wound up at was down at the police station where Graham works.

Also, someone pointed this out on another site that I found interesting, in the orginal pilot draft Graham was originally the one who got Emma to stay in Storybrooke that first night. So I think either way there was a deeper meaning behind both choices.

Yeah, I was thinking that it was the same wolf...which is kind cool. This gives me more hope that Graham & Emma will have a happy ending.

Same here. I feel like Graham's wolf is probably looking after Emma in some ways for him. I hope we see his wolf pop up again.

I really hope so. That's what i think every time I watch the pilot.

Also some people have noted that Emma's story parallels the Ugly Duckling. I personally noticed (looking for more parallels) that in the Ugly Duckling, at one point, a /hunter's dog/ came by and /prevented the duckling from leaving/. But that may just be me.

I always thought that was Graham's wolf. It must have been brought over along with all the other characters and had been living in the forest around Storybrooke for years. It missed Graham, knew he wasn't himself and knew that Emma was needed to break the Curse and restore him, so it prevented her leaving.