Mind Flayer
Mind Flayers were a species that existed in one universe.
Powers and abilities
Mind Flayers possessed the ability to read minds to some degree. They were also able to hypnotize and entrance people.
One Mind Flayer, Cardinal Dracula, possessed a larger set of powers; however, he may have also been a vampire. It is therefore impossible to determine whether all Mind Flayers are capable of the cardinal's powers, or if some of those powers can be attributed to his vampirism. (PROSE: Preludes and Distractions)
History
Cardinal Dracula's Universe
In one universe, a Mind Flayer known as Cardinal Dracula managed to obtain a high position in the church, which he used to corrupt the governing authority of France. (PROSE: Preludes and Distractions)
Earth-44
In a universe known as Earth-44, Alexandre Dumas wrote a version of The Three Musketeers which featured Mind Flayers. (PROSE: Preludes and Distractions)
Literature Exam Universe
In one universe, Jenny Everywhere wrote about Mind Flayers in an essay about The Three Musketeers due to the influence of her alternate selves. Her teacher gave her a B because of this, stating that she had never heard of Mind Flayers, and that there were certainly none in the book in question. (PROSE: Preludes and Distractions)