Ilsensine

In the Dungeons & Dragons roleplaying game, Ilsensine is the patron deity of illithids (also known as mind flayers). While not the creator of illithids, Ilsensine sees mind flayers as the entities most worthy of dominating the universe. Ilsensine is obsessed with gathering knowledge of all varieties, and its ganglia stretch to every corner of existence, tapping into all the knowledge of the universe. The Symbol of Ilsensine is an illithid's head clutching the world in its tentacles.

Description
Ilsensine appears as an enormous emerald-green brain trailing thousands of nerve ganglions off into the distance. It is made of the brains of all the illithids who have died.

Relationships
Ilsensine cursed the derro god Diinkarazan and seeks vengeance against Diirinka, who successfully stole from it. It was formally served by the illithid god Maanzecorian, who was recently killed by Orcus.

Realm
In the standard Greyhawk setting, Ilsensine dwells in a series of caverns beneath the Dwarven Mountain in the Outlands called the Caverns of Thought, along with a vast army of mind-controlled thralls. This realm is intertwined with that of Gzemnid, and stretches near the gate-town of Glorium.

Worshippers
Ilsensine is served by illithids, cranium rats, and eaters of knowledge.

Forgotten Realms
In the Forgotten Realms setting, Ilsensine lives in the Deep Caverns.