Have 21 Zerg units morphing simultaneously in an Unranked or Ranked game.
Win 5 Team Matchmaking Unranked or Ranked games.
Score the rank of Silver in the “For the Swarm” challenge mission.
Complete the “Echoes of the Future” mission with Zeratul killing 50 Zerg units on Normal difficulty.
Play enough qualifying games to get placed in a Matchmaking Ranked League.