Skaarj are 7 to 9 foot tall lizard-like creatures that weigh around 385 lbs. The colour of their scales range from light or dark green to blue or yellow. Different variants of skaarj carry different weapons and are classified in a class-based system. Variants are:
- Warriors - Skaarj armed with twin Raziks, skaarj wrist-blades that also launch electro-magnetic projectiles. They are extremely agile and as such, are used as scouts, assassins and, as their name suggests, warriors
- Troopers - Skaarj armed with firearms that Prisoner 849 (the player's character in Unreal) can pick up. Ranging from basic troopers to snipers and officers, these skaarj are mostly a threat from range.
- Queens - Currently the only known females of the species, Queens are larger and more dangerous than most Skaarj. Able to teleport at will, launch energy blasts from their bodies, or tear a human (or other species) apart with their clawed hands, its hard to believe that they are non-combatants whose only role is the propogation of the skaarj race.
- Warlords - Warlords are an oversized mix of warrior and trooper-class skaarj armed with a rocket launcher and a pair of wings. Similar in appearance to a winged trooper, but with the head of a warrior, they are the main military commanders their respective clans, second only to the clan's queen.
- Pupae - Pupae are newborn skaarj. While you'd expect this to be something to take pity on, remember that the newborns are much more vicious than the adults. Spider-like with the basic skaarj head, they attack with their long legs, but are more of a minor nuisance than a threat.
The Skaarj have only conquered one known planet, and that is the Nali homeworld of Na Pali. They enslaved the Nali to do their biddings, such as mining in for Tyradium Shards. It is possible that they are planning to take over Earth. The only other known conquest is the Izarian homeworld. However, humanity (and most other species not yet under skaarj rule) doesn't know the world's name at this moment.