Straight Outta The Abyss
Demogorgon is a massive demon with a scaled lower body, two baboon-like heads, and massive crushing tentacles. Besides his raw destructive power, Demogorgon has the power to cause mass insanity.
Not much else is known about this demon.
You encountered Demogorgon in Sloobludop where he was being worshiped by a cult of kuo-toa. As you made your escape, Demogorgon rose from the water (while Buppido led a mass eye-removal) and destroyed the town with one swipe of a tentacle. His current status is….a mystery.
Insert Stranger Things reference here.