Heroquest is a classic fantasy boardgame from Milton Bradley, first published in 1989. It is reminiscent of RPGs like Dungeons & Dragons, in that one player is a sort of game master who controls monsters and traps on the game board, while the others control characters who face these challenges. This game master takes on the role of an evil wizard, known as either Morcar or Zargon, depending on the edition of the game.
Important Note: Heroquest is also the name of an unrelated tabletop roleplaying game. If your interest is in the HeroQuest RPG, use that tag instead.