Ravencaller Survivor

When Ravencaller Survivor enters the battlefield, create two 1/1 black Raven creature tokens with "{t}: Target creature gains flying until end of turn.
{b}{1}: Create a 1/1 black Raven creature token with "{t}: Target creature gains flying until end of turn.
Sacrifice two Ravens you control: Destroy target nonBird creature. If it's a Zombie, you gain 2 life.