Out of the Abyss
Prince of Demons, the Sibilant Beast, and Master of the Spiralling Depths, Demogorgon is the embodiment of chaos, madness, and destruction, seeking to corrupt all that is good and undermine order in the muliverse, to see everything dragged howling into the infinite depths of the Abyss.
The demon lord is a meld of different forms, with a saurian lower body and clawed, webbed feet, as well as suckered tentacles sprouting from the shoulders of a great apelike torso, surmounted by two hideous simian heads, named Aameul and Hathradiah, both equally mad. Their gaze brings madness and confusion to any who confront it.
Similarly, the spiralling Y sign of Demogorgon’s cult can inspire madness in those who contemplate it for too long. All the followers of the Prince of Demons go mad, sooner or later.