Yeenoghu

Background
Yeenoghu was a Demon Lord and prince of savagery, the chief being worshiped by Gnolls. He abided within one of the many layers of Hell, and was a bitter rival of Orcus.

Interactions With Mystic Obscura
After Mystic Obscura entered the Abyss, chasing after the demon which had took Lady Eloithe, they encountered Gnolls and killed them. They were eventually brought before the Demon Lord, who informed them he would spare their lives should they head to another level of the abyss, and take a package to an Inn there. Deliver it, and he would not seek this lives in retribution.

Mystic Obscura agreed to do this, and Yeenoghu allowed them passage to another level of the Abyss.