A large brownish creature with a glowing bulbous appendage, the Harvester is a support-type unit that spawns tiny suicidal parasite-like creatures instead of attacking the squad directly. The Harvester itself is relatively fragile and easy to kill, but like the Ranger or Mortarbug, it can be much more effective when supporting other Swarm units, harassing Marines whilst Drones distract them. Harvesters should be taken out quickly to minimize the effect they have on a battle, much like the Mortarbug. When a Harvester is killed, it releases several spawns that fly straight up in the air before they land and attack nearby marines.
- Killing the Harvester while it is burning or frozen will also kill the Spawn it releases upon death.
- Although it cannot attack directly, physical contact with the Harvester causes damage to marines. Coupled with their ability to produce Spawn every few seconds, melee attacks against Harvesters are generally ill-advised.
- When threatened, the Harvester attempts to retreat from battle but continues to produce Spawn. It is advised that you pursue and destroy the Harvester before too many Spawns are produced.
The Xenonite is a small, red and white insectoid that attacks by leaping towards a marine and exploding to shower its target in a corrosive substance. Individually, these Spawn do not pose a significant threat to a Marine, but caution is advised as their attack can knock a marine back and disorient them. Although similar in size, shape and movement to the Parasite, the Xenonite can be easily distinguished by its red and white color in contrast to the Parasite's yellow, and its attack cannot be negated with Electric Armor.