Marath, Will of the Wild enters the battlefield with a number of +1/+1 counters on it equal to the amount of mana spent to cast it.

X, Remove X +1/+1 counters from Marath: Choose one - Put X +1/+1 counters on target creature; or Marath deals X damage to target creature or player; or put an X/X green Elemental creature token onto the battlefield. X can't be zero.