Ivira, Zendikar Reborn

Ivira, Zendikar Reborn enters the battlefield with X +1/+1 counters on her.
{5}{g}{g},{t}: Put X +1/+1 counters on Ivira, Zendikar Reborn, where X is her power.
{t}, Remove X +1/+1 counters from this creature: add X {g} to you your mana pool.