Scourge

The scourge is an aerial zerg kamikaze strain.

Overview
Scourges are blind, suicidal fliers of unknown origin, seeking out enemy starships and diving into them. Catalytic agents within the Scourge allow it to undergo a form of plasma metamorphosis, causing it to explode like a living bomb. A single scourge is capable of destroying a terran starfighter or shuttle and a handful can breach the hull of a starship. They are able to engage these targets in both air and the vacuum of space, though how they are able to propel themselves through the latter is unknown.

The primary drawback of the scourge is its limited ability to store energy, able to fly for barely a few hours without requiring additional substance. To conserve energy, they often perch on the backs of overlords. However, this presents a hazard, as the Scourge's explosive nature can damage friendly zerg at this proximity.

Scourges possess a simple genetic makeup, allowing them to spawn in pairs from a single larva.

Game Unit
Scourge spawn in pairs. Patrolling scourge may help deter low intensity enemy drops. Without supervision groups of scourge tend to lock onto and attack the first target that comes into range which may be overkill against low-HP targets (causing scourge to sacrifice themselves needlessly). This requires careful unit control and direct targeting to avoid. Against more robust targets or groups of targets scourge may be best used to supplement more conventional zerg anti-air units. You can also sacrifice overlords to distract groups so that the scourge can land their strikes.

Although unusual, armor upgrades can also be very beneficial in the late game against mass corsairs.