Description:  The schreki, physically, are similar to Earth insects, but much larger.  Various breeds of schreki have been encountered, but the corpses that have been recovered and studied all show the same basic genetic code.  All schreki seem to have a hive mind, again much like many types of normal insects.  They do not breath, and have extremely adaptable bodies, allowing for survival in G1-3, R0-R2, A1-3, P1-4, H1-3 environments.  Their nests lie deep underground, protecting them from extreme surface temperatures, and as some races have found, orbital bombardment.  The different types are:

Workers:  Usually only 2' tall, these small schreki walk on all six of their legs.  They carry materials with their extremely strong mandibles, and are usually found digging tunnels and expanding the nest's underground area.  Also, they can be found outside of the main enterances of the nests building the mounds up to as high as one kilometer.

Warriors:  The fearsome warrior schreki are the breed most often encountered.  Standing nearly about 5' tall and 10' long, the warriors are death machines.  They walk upon six razor sharp legs, and have a fourth pair of legs that seem to be specifically used for fighting.  These are capable of slicing through most armors and can usually cleave a man in two in very short order.  Their mandibles also are used extensively, being just as sharp and deadly as the combat legs.

Scouts:  Only the t'sa have ever encountered this type of schreki.  They are about 4' long with a 12' wingspan.  These seem to survey an area due to be attacked by the workers.  They aren't helpless however, and if not shot down, have been known to swoop down and grab a t'sa before flying back to the nest.

Egg-Layer:  By far the most alien of the entire schreki race encountered so far, an egg layer is almost immobile.  Measuring 25' long and 14' tall, the egg-layer resembles an insect larva.  Hundreds of small, nearly useless legs line the bottom of the creature, barely providing mobility.  Through it's soft transparent skin, all of its innards are visible.  It doesn't appear to have any sense organs:  no eyes, antenna, etc.  The workers bring food to it (it seems to eat any organic matter, as well as several non-organic substances) and it creates new schreki.  It seems to know when certain types of schreki have been destroyed, as it replaces those first (ie.  Marines blast a few hundred warriors to bits, but no workers, so the egg-layer creates warriors only for a while).  Its reproduction is asexual.

History:  No one has any idea about schreki history, but one thing seems clear:  they are a created race.  So far, League scientists have found no way in which the schreki could have evolved naturally.  The egg-layers travel from planet to planet aboard meteors, they have no variety in their gene pool, and they can adapt to almost any environment.  This stinks of a very advanced biological weapon.  However, no League race, or any race encountered by us, has the genetic technology to have created them.

The schreki encountered humans when they landed on Earth in the mid 21st century.  The t'sa encountered them earlier still.  In each case, a meteor hit the planet and a few days later tons of the warriors poured out and began killing everything in sight.  Many people believe them to be mindless, but xenobiologists think they simply think in a different way than humanoids do.

Psychology and Culture:  None that we know of.  Their philosophy seems to be "All the universe is a hotel, and all the non-schreki merely the free buffet" (to badly paraphrase Shakespeare :).

Racial Characteristics of the Various Breeds:
Workers:
STR 8-13
INT 1 (?)
WIL 4-12
DEX 6-14
CON 9-14
PER 1

Dur 11/11/5
Movement:  Sprint 22, Run 14, Walk 4
Actions per round:  2
Action Check:  12+/11/5/2

Attacks:
Bite:  12/6/3      d4w/d4+2w/d6+2w

Defenses:
Armor (Carapace):  d4 (LI), d4-2 (HI), d4-2 (En)

Skills:
Athletics (11)-Climb (12), Movement (11)-Trailblazing (13), Stamina (11)-Endurance (14), Unarmed Attack (11)-Brawl (12), Acrobatics (11)-Dodge (13), Awareness (8)-Perception (10)
 

Warriors:
STR 10-16
INT 1 (?)
WIL 4-12
DEX 8-14
CON 10-15
PER 1

Durability 13/13/6
Movement:  Sprint 24, Run 16, Walk 6
Actions per round:  2
Action Check:  13+/12/6/3

Attacks:
Bite:   12/6/3      d4w/d4+2w/d6+2w
Combat Legs:  15/7/3      d6+1w/d8+1w/d6m

Defenses:
Armor (Carapace):  d6+1 (LI), d6 (HI), d6 (En)

Skills:
Athletics (13), Unarmed Attack (13)-Brawl (16), Movement (12), Stamina (12)-Endurance (14), Acrobatics (12)-Dodge (14), Awareness (8)
 

Scouts:
STR 4-12
INT 1 (?)
WIS 4-12
DEX 9-15
CON 4-12
PER 1

Durability:  8/8/4
Movement:  Sprint 10, Run 6, Walk 2, Fly 32
Actions per round:  2
Action Check:  13+/12/6/3

Attacks:
Bite:  10/5/2      d4w/d4+1w/d6w

Defenses:
Amor (Carapace):  d4 (LI), d4 (HI), none (En)

Skills:
Unarmed Attack (8), Movement (8), Acrobatics (12)-Dodge (14)-Flight (14), Stealth (12), Awareness (8)
 

Egg-Layer
STR 1
INT 1 (?)
WIS 4-12
DEX 1
CON 11-16
PER 1

Durability:  14/14/7
Movement:  Negligible during combat
Actions per round:  1
Action Check:  5+/4/2/1

Attacks:
Nil

Defenses:
Nil

Skills:
Stamina (14)-Endurance (17), Awareness (8)
 

Racial Advantages
Schreki, as mentioned above, can tolerate many different kinds of worlds with no problem.  G1-3, R0-2, A1-3, P1-4, H1-3 are all habitable by them.
All known schreki (save the egg-layers) have some degree of body armoring

Racial Disadvantages
No fine manipulators, so even if they were smart enough to be able to use technology, they couldn't.