Aragrax, Stony Summoner

Aragrax, Stony Summoner enters the battlefield
with X +1/+1 counters on it.
Whenever you cast a spell, if no mana were spent
to cast it, you gain 3 life.
{3},{t}, Remove X +1/+1 counters from Aragrax,
Stony Summoner: You may cast a spell with
mana value X or less from your hand without
paying its mana cost.