Created during the early years of Dungeons and Dragons and inspired by science fiction the mindflayer (also know as the illithid) is now one of the most iconic monsters of Dungeons and Dragons. These former lords of the multi-verse now hidden have a plethora of information available to state the lore hungry Dungeons Master or Player.
The blog The Monsters Know What They’re Doing has a post which outlines the tactics these creatures would likely use in a combat encounter.
Mindflayers require a host to come into existence. A mindflayer tadpole is placed into a host’s brain usually via the eye. When ready the tadpole takes over the form of the host and becomes a mindflayer the process of which is shown in this trailer for the Baldur’s Gate 3 game trailer.
Mindflayer Spaceships (Spelljammer)