The Mantis Screamers of the desolate Dinares Sector were assimilated into the Swarm as the Mutalisks due to their ability for atmospheric and deep space travel. Having changed little from their original form, it could be concluded that the deadly acid spray they utilise to attack and defend had already been developed prior to their inception into the Zerg race.

The Mutalisk can spew forth Glaive Wurms which seek out nearby targets and punish them. While the initial strike drains the Glaive of most of its damaging efficiency, the resulting 'jumps' can be responsible for minimal injuries, which can become deadly when the Mutalisk strikes in hordes, which is often the case.