A mutalisk is an airborn extraterrestrial in the fictional science-fiction real-time strategy computer game StarCraft.

Mutalisks have a long body and tend to fly with their tails curved forward in an elongated L shape. Their wings sprout from their back. In gameplay terms, they cost 100 minerals and 100 vespene gas to create, as well as two supply. The player must also control a Spire to hatch Mutalisks. They move through air or vacuum quite quickly and possess a unique "Glaive Wurm" attack: these bladed disc projectiles will bounce off an initial target and strike two more before disappearing, each time doing successively less damage.

The Mutalisk is a versatile unit used both for hit-and-run attacks and full-on assaults. Because of its small size, it deals well with explosive damage (which is decreasingly effective against smaller units). Later, if the Spire is upgraded to a Greater Spire, the Mutalisk can morph into a Guardian, a dedicated long-range bomber; and, in StarCraft: Brood War, it can turn into a Devourer, which excels at countering enemy air units. Because of its speed, multi-hit attack and relavitely low position on the tech tree, the Mutalisk itself is often used to harass enemy resource gatherers in an effort to bring the enemy quickly to their knees by depriving them of vital resources.