- "Frankly, other than the fact that they want to kill every man, woman and child out there, we know nothing about them. We've tagged them Locusts since this degree of death has only been seen in times of plague. They're subterranean in nature. That's obvious. Aside from that, I'm afraid..."
- — Human Scientist dubbing the name of the Locust Horde
The Locust (Latin: Exitosus macipium, meaning "Destructive Slave") are a race of reptilian humanoids native to the human colony world of Sera that until Emergence Day, appear to have remained in the subterranean regions of the planet. The Locust Horde has decided that its secondary goal is the extermination of the human race down to every man, woman, and child. The Locust Horde's primary goal is to populate the surface of Sera. The Locust wage a tactically beneficial war of genocide against the Humans due to the existence of a civil war between the Locust Horde and the Lambent Locust. This civil war has been going on for an undetermined amount of time, and is gradually forcing the Locust out of the Hollow and into a war with humanity over who controls the surface world.
All known attempts at negotiating with the Locust Horde have ended in violence, although Adam Fenix believed he could end the war peacefully. The Locust consist of a common race of drones and all manner of other animals that are indigenous to the underground tunnels known as the Hollow, which is a short term used to describe the hollow portions of planet Sera which is mainly controlled by the Locust Horde. Under Mount Kadar is the Locust capital Nexus.
The majority of the Horde's technology was stolen or salvaged from what the Humans dumped. It appears to be at around the same level as that of humans minus the interstellar capabilities with similar firearms, although the Locusts' arsenal seems to be more biologically based with the use of Tickers, Nemacyst, Brumaks etc. Locust troops will use nearly any weapon, whether it is one of their own design or human-made.
A typical Locust is a hulking brute of a creature, over 7 feet tall, although many are larger. They are bipedal, muscular creatures, with tough skin. They were considerably more bulky than a normal human and notably stronger physically. Their bones were heavier and show signs of extensive thickening. Grenadiers show further toughening and occasionally scarification, which appeared to further toughen the Locust's flesh.
Locust Blood is a deep reddish-orange in coloration. A Locust had multiple internal organs, as hinted by hearing multiple heartbeats from a given Locust when they run or are at critical health. Locust required oxygen like any other species, though they seemed somewhat more resistant to environmental hazards, most likely due to their harsh environment.
Locust had large eyes with good depth perception in spite of the fact that they are a subterranean race. They had a noted vulnerability to flash overcompensation response (Flash-blindness), a weakness many offset with polarized goggles or blinders. Some subspecies had particularly strong eyesight and incredible depth perception; it is strongly hinted that Locust can see perfectly in total darkness, and most seemed to possess superior senses of smell.Berserkers and Myrrah were the only known female Locust. The only known method of Locust reproduction is the mating of a Berserker and a Drone by tying the female down and raping her to prevent the blind beast from killing her mate.