Link for reference.
We've got a few possibilities:
--Alduin because eating the world is kind of his thing and the lorebook was in Eastmarch
--Hircine, because it's a wolf
--Satakal because, again, the world eating
--The Celestial Serpent for along the same lines, plus the story specifically mentions trying to devour the stars
Mara IIRC was occasionally depicted as a wolf but it seems a bit out of character for her.