Creatures

Neomorphs
Neomorphs, while similar to Xenomorphs in their behaviour, they are less evolved and far more animalistic. They posess very little social structure and do not demonstrate the same hive mindedness as Xenomorphs. They seem to be driven by the most basic of needs and are incredibly hostile.

Blood Buster
Blood Bursters are the Neomorphs equivilent of a Chest Burster.

Face Huggers
Face Huggers are a living delivery system for Xenomorphs to impregnate pawns with Chest Bursters.

Chest Bursters
Chest Bursters are embryotic Xenomorphs, that literally burst from the hosts chest when born, causing death.

Rhynth
Rhynths are a beast of burden creature used by humans.

Thrumbomorphs
Thrumbomorphs are the result of the impregnantion of a Thrumbo by a face hugger, causing a mutated version of a Xenomorph. They are part of the Xenomoprh hive mind.