Not a mindflayer, it's an Ascended Sleeper.
There's a mass of Morrowind references in the new DLC, and it looks like some older faces showing up. Telvani architecture as well. Cautiously optimistic about this DLC, likely to do one of three things: Get the Morrowind stuff right, thus being awesome ; not get the Morrowind stuff right, which'll annoy those who like Morrowind, but have good mechanics and gameplay ; not work at all and fail completely.
Hoping for the first option, though the second option'll be cool as well.