The Swarm is an alien species characterized with animal, mostly insect-like, features such as carapaces, appendages and segmented bodies.
The sizes of Swarm organisms vary from really small ones the size of average dogs to lumbering giants as tall as buildings. No matter the size, a typical Swarm organism's weapons are their claws and mandibles. These natural weapons are extraordinarily strong and sharp, able to rend steel and pierce metal with relative ease. Specialized organisms are able to spew acidic bile or fire bony spikes at foes.
Planets conquered by The Swarm are consumed of all life and replaced with Swarm creatures and organic structures. Anything living, animal or plant, are killed and their corpse taken to some sort of pit or pool of digestive fluid where they are broken down and presumably become nutrients to sustain The Swarm. It is widely-believed this is the main plan of The Swarm at large; to simply consume everything organic in the universe.
The intelligence of The Swarm is still being debated. Some theorize that The Swarm is united with a single, massive intelligence like a Hive Mind while others think that each Swarm organism has free will but follow a hierarchy and a few believe it's somewhere in between. But all agree on one thing, The Swarm is no mere collection of animals. They are capable of high thought, able to form tactics and strategies against their enemies.
The organisms of The Swarm usually vary heavily from each other, making it impossible for hard classification and identification. However, there are creatures that appear consistently enough to be identified.
Rippers - These relatively small creatures come in hordes to swarm enemies. While relatively easy to kill, their claws and mandibles can cut through hard materials.
Spikers - Creatures that can quickly grow bony spikes and shoot them at foes. They are not very accurate but they usually come in high numbers, offsetting the weakness.
Tyrant Rexes - Named after the famous dinosaurs of old, these giant creatures can flip tanks and knock down walls. A favorite tactic of The Swarm is to send Tyrant Rexes with smaller creatures. The smaller ones can distract enemies while the Tyrant Rex does the damage.
Stalkers - Unlike a typical Swarm organism, these creatures seldomly appear in open battle. Instead, they are mostly found infiltrating bases and disrupting them from within. As such, they are adept in stealth and can be very quiet in their movements.
Alphas - Unique among The Swarm by having a distinct coloration about them. Alphas are normal Swarm organisms that have additional abilities and features. They are believed to be elite units of The Swarm since they appear rarely.