The mutalisk's attack strikes three targets in succession, dealing 9 damage to the first, 3 to the second, and 1 to the last. Unlike many other air units, the mutalisk is small with light-type armor, making it more resistant to explosive damage, a common damage type found on anti-air units like dragoons and goliath. The mutalisk deals normal damage and is only affected by the armor of the target. Compared to the wraith and scout, the mutalisk's attack is weaker and more easily affected by armor.
Large groups of mutalisks tend to clump together making them ideal targets for attacks or abilities dealing area of effect or splash damage. Mutalisks are fast, but accelerate slowly making it harder to escape; this improves the effectiveness of the high templar's psionic storm against mutalisks. archons are likewise a good counter against mutalisks due to the splash damage of their psionic shockwave. On the other hand, stacking mutalisks does make them easier to control, and can make it harder for single target attacks to deal with them (e.g. marines). One can trick mutalisks into stacking by including an overlord in the control group.
Corsairs and valkyries are also effective against mutalisks due to their splash damage attacks.
Mutalisks become available to the player in the campaign with the mission "Egression" in Episode II and "Vile Disruption" in Episode VI. Mutalisks can morph into guardians to devastate ground units and morph into devourers to take down battlecruisers and carriers.
Sound files suggest that the mutalisk was originally called the "mutalid."[1] Originally, the mutalisk was armed with an "acid spray" attack rather than glaive wurms.[2] It can also be seen in the Death of the Overmind, the final cinematic for Episode III where mutalisks attack the Gantrithor.[3]
