Vampiric mind flayer

The origins of these unique undead mind flayers are unclear. All that is known of these creatures is that they cannot create spawn, need both fresh blood and fresh brains to survive, are more feral than typical illithids, and are barely intelligent. One possible origin is given in the Ravenloft adventure Thoughts of Darkness, in which a vampiress collaborates with the illithids in using the Apparatus to create the first vampiric illithid, a being never conceived of before. Whether they spread from the Demiplane of Dread or not is another matter, what can be said is that these creatures are hated and feared by typical illithids.