Yeenoghu

Yeenoghu is a specific demon from the Abyss. A creature of pure chaos & destruction, he is part animal part humanoid in appearance, and a demon lord. He appears as part hyena, or canid even to some, and a ferocious bloodthirsty creature that revels in the destruction of mortal flesh, and loves nothing more on feasting on fresh kills. The Gnolls of the Material Plane, and some cults worship him, and are driven to destroy all life, and feast on the remains when they can.
A cabal of African Witchdoctors, Middle Eastern Warlocks, and Indian Dayan summoned him to the Material Plane. This led to mass destruction before he was sated enough to return to the Abyss. Ever since his mass genocide, and the creation of the Gnolls from hyenas that fed on his kills, elements watch for him possibly coming into the Material Plane again.