Get it off can have a series of meanings.
Some of them are "exit/leave/take a walk/quit/go away from (me, in this case)"
Since there is a exclamation point, things get dramatic, let´s say one would scream "go away! or "get lost!" ''get out", something like that.
To clarify things further, you can see by this discussion on Wordreference, that they translated it into "
Véte para allá. (actually a contraction that sounded more like véte pa' ya)==Move over." (vai pra lá! )
and to "Quitatelo".
So, to my thinking "get if off" would mean "vaza! sai fora! dá o fora daqui! ) in a scary situation someone can say anything...wheter of not the wolf is going to obey him is another can of worms altogheter!