Source: Unearthed Arcana 11 - That Old Black Magic
4th-level conjuration
Casting Time: 1 action
Range: 60 feet
Components: V, S
Duration: Up to 10 minutes
You summon a barlgura that appears in an unoccupied space you can see within range. The barlgura disappears when it drops to 0 hit points or when the spell ends.
The barlgura is hostile to all non-demons. Roll initiative for the barlgura, which has its own turns. At the start of its turn, it moves toward and attacks the nearest non-demon it can perceive. If two or more creatures are equally near, it picks one at random. If it cannot see any potential enemies, the barlgura moves in a random direction in search of foes.
As part of casting the spell, you can scribe a circle on the ground using the blood of an intelligent humanoid slain within the past 24 hours. The circle is large enough to encompass your space. The summoned barlgura cannot cross the circle or target anyone in it while the spell lasts.