Yargtusk Mana Gatherer

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Converge - Yargtusk Mana Gatherer enters the battlefield with a +1/+1 counter on it for each color of mana spent to cast it.
Whenever Yargtusk Mana Gatherer attacks, you may remove any number of +1/+1 counters from it. If you do, add one mana of any color to your mana pool for each counter removed this way.