An infestor uses 25 energy to deploy an infested swarm egg a short distance away; the infested terran hatches five seconds afterwards. An infestor may deploy as many infested terrans as energy allows.
Infested terrans have short lifespans and move slowly, but have slightly better health and attack power than marines. Infestors may spawn infested marines while burrowed, enhancing surprise and utility for economy raiding. Infested terrans provide on-demand firepower against ground and air targets.
In Patch 4.0, the infested terrain's gauss rifle was made to only target ground units, and they were given the infested rocket ability, doing heavy damage to air from a longer range. Infested marines were also made to benefit from ranged and carapace upgrades.