Bloodwrack Demons

Bloodwrack demons are wicked, bestial demons used much like savage guard dogs by infernal warriors and dark spellcasters. They generally stand eight to nine feet tall on two legs, but often spring on all fours and use their curved, goat-like horns to gore their foes.
Unlike most demons, a Bloodwrack demon is usually crafted intentionally. They instinctively use their blood magic to bind themselves to an ally and use this link to protect their ally from harm.

Hunter's Notes

The hemomantic ritual performed by a Bloodwrack demon serves to protect the fiend's ally as well as the fiend itself. The first hunter to stumble upon a Bloodwrack demon noted an unpleasant surprise: upon the death of the Bloodwrack or its ally, the hemomancy that once bound them snaps, and dramatically strengthens whichever of the two still stands. Dispelling the bond is ill-advised.

Gatherer's Notes

Bloodwrack demons are among the few "naturally" hemomantic creatures. Their blood is valuable for bloodcrafters and dark wizardry, notably Bloodwell Vials.