The first of all Tanar'ri, born of the primal fears of the first mortal souls and said by the Koprus to have been born of two mothers, Prukal and Shothotugg, Demogorgon embodies enervation, madness, reptiles, and aberrations. After becoming a hero of the war of the tanar'ri against their Obyrith predecessors, Demogorgon earned the right to call himself Prince of Demons, a title he has successfully defended from all those who would take it from him.
The fiend-lord manifests as a two-headed, reptilian beast with hideous mandrill heads and lashing tentacles for arms. He is worshipped by tanar'ri, the mad, the deformed, reptiles and apes, and the ixitxachitl and kopru races. His Layer in the Abyss is known as Gaping Maw.
For millennia, Demogorgon has feuded with his rivals Orcus and Graz'zt over rulership of the Abyss, but Demogorgon's two heads each have wills of their own, occasionally pulling him in contrary directions.