Battle.net

Attack for 20 seconds with no counterattacks in an Unranked or Ranked game.

Kill 15 enemy units with a single Nuke in an Unranked or Ranked game.

Kill 5 Changelings in an Unranked or Ranked game.

Heal 5,000 life with Medivacs in an Unranked or Ranked game.

Kill a Stank before it kills anything on Hard difficulty.