Zerg Spire

{3}{g}{u}: Larva Mutation - Remove 1 Larva counter from a controlled Zerg Hatchery, Zerg Lair, or Zerg Hive to create 1 1/4 green and blue Mutalisk creature token with Flying.

{3}{b}{b}{u}: Mutate into Greater Spire - transform this artifact into a Greater Spire.