Ineffable horror

An ineffable horror was a large and terrifying aberration that prowled the Underdark.

Description
Ineffable horrors body resembled that of an ogre, with a head that looked like that of a mind flayer. Growing from its back was a pair of large, bat-like wings. A physical feature unique to ineffable horrors was that its intestinal track was external, appearing as a writhing mass where its abdomen would normally be.

Combat
Ineffable horrors hunted in groups called murders. They used their size and strength to drag a victim within reach of their intestines, which wrapped themselves around the unfortunate target.

Ecology
Ineffable horrors fed on the blood of their victims. When a target was wrapped in their intestines, their blood was rapidly drained.