Guardians are the more advanced air units available to the Zerg swarm only after the majority of the base has been built. Like the Lurker, the Guardian is not created by a Larva but morphs from a Mutalisk instead. However, once they are available to the Zerg swarm, they are used quite frequently.

The Guardian does decent damage but it has a huge attack range and have very little to fear against ground attacks. They can even fire outside the range of defensive structures, making them the perfect units for storming enemy bases. A few dozen Guardians will have no problem sweeping though a base or a wave of ground enemies. Although building a massive Guardian force can be costly, it is still better to have a few around on offense. They perform exceptionally well when used with support units such as Mutalisks or Hydralisks. A few Guardians can help against several enemies which tend to be trouble against ground forces such as Siege Tanks, Reavers, and defensive structures.

Guardians are not to be left alone without help because they lack an air attack. While they can be used to attack empty bases and areas which may look safe, keep in mind they are very slow. Thus if your Guardians suddenly become under attack by a small air fleet, chances are you will not be able to retreat them to safety.