Swarm Maiden

When Swarm Maiden enters you may pay {b}{g}. If you do, it enters with a +1/+1 counter and a death touch counter.

{t}, Sacrifice each creature you control named
Swarm Maiden: Create X token copies of Swarm Maiden where X is equal to the greatest power
among sacrificed creatures. Then if you control only one creature named Swarm Maiden, put X +1/+1 counters on that creature.