Illithid references in Baldur's Gate 1

Illithid Baldur's Gate

Illithid aka mindflayers do not appear in the original Baldur's Gate 1 as a monster to fight, but there exist references to Illithid in Ulgoth's Beard and Durlag's Tower of Tales of the Sword Coast.

Fenrus at Ulgoth's Beard:

Fenrus Boulon has told us that Durlag's Tower was built by a famous dwarven hero name Durlag Trollkiller. The wealth that he amassed was coveted by a group of mindflayers, who used dopplegangers to kill and replace Durlag's family. The hero killed the beasts but was driven mad in the process. He entrapped the Tower and disappeared within its depths.

... dopplegangers, organized and aided by foul mind-flayers, slew and impersonated Durlag's companions.

In the end, alone and victorious, he was powerless to stop the fleeing illithids. Fearful they'd return, Durlag hired the finest craftfolk he could find and began to rebuild his tower and the tor beneath as an elaborate succesion of traps, magical wards, secret passages, sliding prison chambers, and triggered weapons.

Durlag's Tower: References to an illithid incursion (third passage):

It began with usssss...and the mastersss...The tentacled ones directed and we assssaulted quietly with cover of night.

BG1 Index.