Demogorgon

Demogorgon is believed to be one of the oldest and most powerful of the Demon Princes. He rules some of the deepest areas of the Abyss, mostly characterized by roiling seas, jungle islands, and smouldering volcanoes. He has a hugely powerful body, furred like a great ape, with tentacles instead of arms. His lower half is similar to that of a forked-tail reptile. He has two heads with distinct personalities and names, Aameul (the deceiver) and Hethradiah (the destroyer). Cults of Demogorgon often kidnap twins for sacrifice to this demon lord of duality.
Some say that Demogorgon was a powerful Primordial, corrupted by the Seed of Evil that created the Abyss and one of the first to fall to its influence. Others say that Demogorgon was born out of the Seed itself. Whatever the truth, few dare oppose this potent Prince of Demons.