Scholarleech

The most intelligent of the demishades, the Scholarleech is nonetheless driven to seek the aid of higher brainpower than its own, stunning potential hosts with a shock from its single arm before engulfing the subject's cranium and drilling its long, coiling tendrils into the brain and spinal column, employing process remarkably similar to the dreaded brain flukes to integrate with the host mind and body. Even upon detachment from a host, the creature leaves behind enough of its bodily material to maintain long-distance mental contact, accessing any information it desires or simply using the victim's mind for supplementary cognitive processing.