Psion

psion is the d&d way of saying psychic.

it is a common opinion that psions in d&d are overpowered, and considering a common ability of theirs is mind control...well, say what ya want about gamers, but they are an imaginative bunch and the uses of mind control are probably endless.

notable psionic monsters in d&d are mindflayers, who are only seen when one of the players had relations with someone close to the GM.