I wrote this up a while back and seeing if it asmuses.
A buddy of mine was interested in creating an aberration ecosystem and after some stewing, I created this. It uses the various dungeons and dragons monster manuals from 3rd edition. :)
including this for ease of identification.
1. Deepspawn Mother (new creation): Cross a Deepspawn with an elder brain. Telepathically linked to all of her children
2. Deep Spawn (standard): her daughters. They are usually act as advisers and to breed new "children".
3. Grell: The philosophers and advisers of the Mother. While they are active as hunters, they are more often then not Grell philosophers that often double by taking the hat of mad scientist as well.
4. Cloakers: the sentries of the Mother. They often watch and report back what they see.
5. Gibbering Mouthers: believed to be the most favoured of the Mother, they are more often then not thrown in with prisoners to teach their victims, the folly of their ways.
6. Skum: What the Mother makes from the victims of the gibbering mothers. a slave race that tends to the "good work."
7. Piercers/Ropers: The ropers often after as support structure for the Mother's dwellings.
8. Maulgoth: The diggers of the Mother. They hollow out the earth so the rest can live in there.
9. Ocularon: one of the many experiments of the Grell Philosophers. It is used much like a land mine and is directed where needed.
7. Rurkanyr: created when the Mother needs to go on the offence.
8. Skybleeder: used as the "airforce" of the Mother's forces.
9. Slashath: kept as pets by the Mother's forces.
10. Tunnel Terror: sometimes it's just easier to fill a corridor with a giant worm and let it eat invaders.
11. Avolaki: used as an invasive species on enemy territory . these nauseating creatures are used to soften forces by capturing enemies and using for breeding stock.
12. Fihyr: the Mother collects the psychic terror of it's victims and creates these from the essence.
13. Hook Horror: if we could communicate with them, we might find a sympathetic ear. They are the gardeners and overseers of the Skum.
14. Meenlock: When the Mother wants to create something other then skum, this is one of her many experiments.
15. Moonbeasts: the treasurers of the Mother. They take inventory of the spoils of war and exploration. Their Obsession is ingrained in their nature.
16. Wystes: used as a food source for many of their other children. It is produced by the ton and kept in huge breeding pools.
17. Quaraphon: These full fill the "ogre niche" in the mothers culture. these brutes are created and sent out to scour the land.
18. Rot Reaver: created to eat the dead and undead. Many a vampire or lich was absolutely blindsided by armies of these creatures when they were produced by the Mother.
19. Runehound: The trackers of the Mother. often sent out to track down creatures that flee.
20. Serylum: used as a defacto navy in the many underground lakes and oceans.
21. Shrieking Terror: used as a weapon when the Mother's anger is raised.
22. Stonesingers: The bard's of the Mother's court. She finds their music soothing while it drives others insane.
23. Carrion Crawler: These are very common in the Mother's settlements as they are scavengers that are sometimes harnessed. They almost have the goblin niche.
24. Chuul: The "marines" of the Mother's forces.
25. Grick: They are used as short term patrols
26 Mimics: The personal shapeshifter of the Mother. They act as guardians, but there is rumours of an intelligent version that acts as the Mother's personal assassin (think john carpenter's the thing).
the Aboleth's, Beholder's and Illithids, while they have their own communities, pay respect to the Mother for in all of their tales it was her that created them from the primordial ooze of creation. The Aboleth's genetic memory confirms this as they were created as "storage" devices by the Mother so they would always remember.
feel free to grab what works and tweak what doesn't.