The beholder is a fictional monster in the Dungeons & Dragons fantasy role-playing game. It is depicted as a floating orb of flesh with a large mouth, single central eye, and many smaller eyestalks on top with powerful magical abilities.

The Monster Manual is the primary bestiary sourcebook for monsters in the Dungeons & Dragons fantasy role-playing game, first published in 1977 by TSR. The Monster Manual was the first hardcover D&D book and includes monsters derived from mythology and folklore, as well as creatures created specifically for D&D. Creature descriptions include game-specific statistics, a brief description of its habits and habitats, and typically an image of the creature. Along with the Player's Handbook and Dungeon Master's Guide, the Monster Manual is one of the three "core rulebooks" in most editions of the D&D game. As such, new editions of the Monster Manual have been released for each edition of D&D. Due to the level of detail and illustration included in the 1977 release, the book was cited as a pivotal example of a new style of wargame books. Future editions would draw on various sources and act as a compendium of published monsters.