Beholder

A beholder is a large aberration normally found in the Underdark. These large, orb-like beings have ten eye-stalks and one central eye, each containing powerful magic. Vicious creatures, beholders are quick to attack enemies, which include anyone it deems not "like themselves."

Beholder Magic
The beholder's magic originates from each of their eye-stalks and its central eye. Each of their eye-stalks can cast one of ten spells on a single target as if casted by a thirteenth level caster. The central eye of the beholder also has a powerful antimagic cone. It constantly emits a 150 foot (46m) cone that effects all within it, including the beholder, as if by the spell antimagic field. The beholder choses to turn this field on or off once every few seconds by opening or closing its central eye.

Sane Beholders
Beholder minds are divided into two separate entities. Each of these entities thinks and acts on its own accord even though it is bound to the same body as the other half of its mind. Neither half of the beholder's mind trusts the other, so they hide a lot from each other, creating a very paranoid relationship.

"Sane beholders" are beholders whose minds are not "divided" so to speak. There are still two entities within the beholder, but neither hides anything from the other, making a less paranoid beholder. However, the persona of a "Sane beholder" is just as likely to be considered "insane" by anyone else as the persona of any other beholder.

Because there are two entities within a single beholder, that beholder should always be recognized by its full name when in conversation with them, or they will perceive it as speaking to only one of the entities. For instance, a beholder named "Orbius Eyebiter" should be addressed as such or one is only speaking with "Orbius" or only with "Eyebiter."