Continuity mistake: Near the end, when the Doctor is explaining to Amy that she will forget Rory when the crack in time is finished eating him because he's part of her personal timeline, and he has his hands on her temples, Amy's hair is covering her ears in some shots, but not others. (00:40:56)
Continuity mistake: When Ambrose, while standing with Elliott, admits to killing Alaya, in the first shot, Elliott is standing in front and to the right of Ambrose. In the second shot, he's standing to her left. (00:27:52)
Chosen answer: No, no information is avalible for the identity of the entity.
Repo_Man