In the Dungeons & Dragons fantasy role-playing game, the term monster refers to a variety of creatures, some adapted from folklore and legends and others invented specifically for the game. Included are traditional monsters such as dragons, supernatural creatures such as ghosts, and mundane or fantastic animals. A defining feature of the game, is that monsters are typically obstacles that players must overcome to progress through the game. Beginning with the first edition in 1974, a catalog of game monsters (bestiary) was included along with other game manuals, first called Monsters & Treasure and now called the Monster Manual. As an essential part of Dungeons & Dragons, many of its monsters have become iconic and recognizable even outside D&D, becoming influential in video games, fiction, and popular culture.