Barka, Host of Horrors

Flying
Whenever Barka enters the battlefield and at the begining of your upkeep, you gain 2 life.
At the beginning of each end step ,you may pay
{b/g} and X life,where X is the amount of life you
gained this turn .If you do, create an X/X green
and black Saproling creature token with trample.
{1}{b/g}{b/g},sacrifice a creature:Put X +1/+1 counters
or X -1/-1 counters on target creature, where X is
the sacrificed creature's power.