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.[1]
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.
Versus
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.
The infestor does not have the ability to create infested terrans in the campaign. Instead, these are produced from garrisons infested by virophages.
Co-op Missions
Alexei Stukov is able to construct infested marines from his infested barracks. These marines have a timed life, but deal high damage and are rallied alongside infested colonists with his psi emitter ability. Stukov also gets infested troopers, which are identical to infested marines, but are spawned for free from the infested bunker and have a shorter timed life.