Chronicles of Khaldun: Bread and Circuses
Yeenoghu, the Demon Prince of Gnolls — also known as The Destroyer, the Beast of Butchery, the Ruler of Ruin, the Lord of Savagery, and the Prince of Demons — is the demonic patron of gnolls, whom they worship as a god. Lord of the 422nd level of the Abyss, Yeenoghu is known for his savagery. In addition to gnolls, Yeenoghu is also worshiped by ghouls due to his subjugation of Doresain, the King of Ghouls.
Some claim that there were originally other gnoll deities, and Yeenoghu usurped their positions, while others claim that it was always Yeenoghu, and that he created gnolls from his own demonic essence.