The Mindflayer is a creature of nightmare and horror. It was seen peering through the enchanted mirror into the chapel in Xanathar Sewer Hideout when the adventurers raided it and rescued Lord Renaer Neverember.

Mindflayers, or Illithids, are evil and sadistic aberrations. Dwellers of deep Underdark areas, these alien humanoid-looking beings sought to expand their dominion over all other creatures, controlling their minds to use them as hopeless slaves and devouring their brains for sustenance.