The Cave of Monsters (魔物の洞窟 Mamono no Dōkutsu?) is a recurring location in the Bubble Bobble series. Located in an area known as the Wizard's Forest (魔法使いの森 Mahōtsukai no Mori?), the cave has one hundred levels, and is filled with monsters and treasure, with the cave's master, Super Drunk, making his lair on the bottom floor.
The Cave of Monsters is a mysterious cavern located deep in the Wizard's Forest, and has one hundred floors, each with their own unique layout. Many of the floors have unique appearances, with some covered in brightly colored tiles, and others resembling a more traditional depiction of a cave, with the walls and floors appearing to be made out of rocks. Additionally, several Secret Rooms are hidden throughout the cave, each filled with treasure and a message written by Super Drunk. The cave's 100th floor is home to Super Drunk himself, and in Bubble Bobble: Old & New, it has stained glass windows adorning the walls. Additionally, in Final Bubble Bobble, a chapel is shown to be located on the bottom of the cave.
Long before the events of the Bubble Bobble series, the Cave of Monsters was home to a large number of monsters that caused havoc on the world. Intent on stopping their reign of terror, a powerful warrior battled his way through the cave in an attempt to drive the monsters back and seal them inside the cave forever. However, one monster escaped before the seal was placed, eventually growing in power and becoming known as Chaostikhan. At an unknown point in time, Super Drunk took control of the cave.
The first appearance of the Cave of Monsters is in the original Bubble Bobble, in which Bub and Bob's girlfriends, Betty and Patty, stumble upon the cave after getting lost in the Magical Forest, and are abducted by Super Drunk. After being transformed into Bubble Dragons while trying to rescue the girls, Bub and Bob follow Super Drunk down into the cave and set out to conquer its one hundred floors in order to save Betty and Patty.
The Cave of Monsters does not appear in Parasol Stars directly, but its backstory is revealed in the game's manual. In the events of the game, Chaostikhan finally returns to the cave, having gained enough power to break its seal, and sets the monsters free to wreak havoc on Rainbow World and its surrounding planets. Bubby and Bobby set out with their newly acquired Magic Parasols in order to free the various planets from the monsters' terror and stop Chaostikhan once and for all.
The Cave of Monsters is mentioned in the intro to Bubble Bobble Part 2, however, the game simply re-uses the intro text from the original Bubble Bobble, as the cave does not appear as a level in the game.
The Cave of Monsters reappears in Bubble Bobble: Old & New, a remake of the original Bubble Bobble. Many of the cave's floors have received visual makeovers in the game's "New" mode, now bearing more intricate designs and details instead of the usual black backgrounds with colored platforms that the original game featured.
The Cave of Monsters features as the setting of the Classic Mode of Bubble Bobble Plus!, which is another remake of the original Bubble Bobble. Unlike Old & New, it retains its initial appearance.