Illithid

Illithids are cool; and by cool, I mean totally sweet. They look like Cthulu, wear purple robes with high collars and eat brains. Plus they all have psionic powers and are so super-smart even their breakfast is JUST AS PLANNED! They would be totally Mary Sue, except for the fact that they are so brain-damagingly evil it makes them awesome instead of lame.

The Illithid is considered "Product Identity" by Wizards of the Coast and as such is not released under its Open Game License

Unified Setting Description

Once the Illith were a happy aquatic race, singing songs while they scampered about on the ocean floor, happily gobbling whale shit for their sustenance.

Then the goblin race fucked up, badly, and in an effort to stop the world from ending DROPPED A CONTINENT ONTO THE OCEAN FLOOR!

For surface dwellers it was no big deal. Some tidal waves, a lot of land subsided and became swamp, and a bunch of refugees. On the plus side, new trade routes were opened. For the illith? Massive shockwaves and turbidity nearly wiped them out. It was a combination of the Yellowstone super-volcano going off, the crash of SDF-1 from Robotech and an invasion of Nazi hell-creatures.

The former goblin homeland contained a lot of lootable magi-tech, but it also brought with it a bunch of dangerous liches trapped by Bongo Bongo, the frankengod they had created to save the world from their own folly. The liches and the illith did not get along.

War erupted, and while being aquatic and lacking fire and smelting, the illith were not without resources. They had the vast biological resources of the ocean and a knack for selective breeding. Spider crabs were transformed into strength-enhancing exoskeletons. Sea snails were turned into venomous daggers. Mantis shrimp were turned into instruments of pure concussive destruction.

Gradually the illith got the upper hand, and while not able to eliminate the goblin liches, were able to create a stalemate. Using their newfound freedom they investigated the surface world which had visited such horrors on them and found it wanting.

Now, equipped with the war-gear they have developed over centuries, the illith jihad or illithiad makes war. The surface world so far is ignorant, seeing only missing ships or vanished fishing villages. But when the time is right the surface world will tremble at the coming of the illithiad.