Devouring Whipvine

Whenever a land enters the battlefield, put a +1/+1 counter on Devouring Whipvine.
{b}{g}, remove two +1/+1 counters from Devouring Whipvine: Devouring Whipvine deals 2 damage to target creature or planeswalker, and you gain 2 life.
If the vines don't kill you, its fangs will.