I have a riddle that i can't figure out the answer to.?

[Faythe]

Its a harry potter riddle.

I seem innocent at first glance,
But Watch out! I could be a foe.
Don’t try your luck alone or untaught,
There’s much about me that you’ll need to know.

Battle me and you may win your prize,
Lose and I may eat you alive.

When the enemy is great enough,
I may even join your side!

Any ideas? Reasoning?

[RadhaM]

umm... quite hard... but I think it must be somone who seems friendly but not a friend... like Snape? i am not sure... Sorry! D=

Hope I helped!

[Kt:]

Lupin, maybe? He seems innocent at first glance, but he's actually a werewolf and to be around him alone could be deadly. But that just might not be, it fits some of the riddle, but not all.