Well if it's mimicking the actual scene:
YouTube - Snow White part 1
(last two minutes of the vid)
then it could only be the Huntsman (or his horse). But it obviously isn't since it's too small and off colored.
It's probably just a part of the scenery.
You know what would be interesting though? What if Terra met the Queen first, and she convinced him to try and kill Snow White perhaps portraying Snow White as evil (but then he realizes she's a being with pure light). So essentially Terra would be taking the Huntsman's place. It would go along nice with the whole concept of Terra thinking he's doing the right thing when he's actually not (as we've speculated).
