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 (also known as Mind Flayers) who have died. While not the creator of the Illithids, it sees the creatures 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. In the standard Greyhawk setting, Ilsensine dwells in the vast Caverns of Thought beneath the Concordant Domain of the Outlands, while in the Forgotten Realms setting it lives in the Deep Caverns. The Symbol of Ilsensine is an Illithid's head clutching the world in its tentacles.
