Big Boo's Haunt

Big Boo's Haunt, also known as Big Boo's Mansion, is a three-story mansion owned by the Big Boo located in a small cage. It is the fifth course in Super Mario 64 and Super Mario 64 DS. Instead of accessing the course via a painting, the player must travel to the castle's courtyard after they has collected twelve Power Stars (fifteen in the DS remake) and defeat the Big Boo containing a small cage. When near the cage, the player's character with shrink down and enter it.

In Super Mario 64 DS, this is the only main course Yoshi cannot access entirely, since he cannot defeat or eat Boos.

Layout
Big Boo's Haunt takes place within the cage. There are two buildings in the course: the main mansion and a shed off to the side. Around the mansion are several Scuttlebugs and an entrance to a secret room with a couple of Boos is at the back of the mansion.

The mansion consists of three floors, though only the first floor is accessible during the first mission (unless the player has unlocked Luigi in the DS version, in which case the player can easily jump to the next floor). The rooms of the first floor consists of, from left to right, a room with the Mad Piano, a library, a dungeon, a room with a falling bridge, and a room with a large hole and some platforms. If the player falls into one of the holes, it will lead them to the Merry-Go-Round area underneath. Once all the Boos and the Big Boo on the first floor are defeated, a staircase to the second floor will appear.

The second floor has the same amount of rooms as the first, as well as the course's Star Marker. The second door from the left leads to a large library with books flying out of the shelves, trying to attack the player. The end of the library leads to the first room from the left, which contains a Power Star. The third room has a wire-frame grate floor above the dungeon room, the fourth room has several coffins that will rise when the player approaches them, and the fifth room contains a bookcase with Bookends and a large, turning platform that will drop the player into the Merry-Go-Round area if they stand on it for too long. The door in the back of the fifth room leads to a blue ! Block (or a red ? Block in the DS version) and a door above on a ledge leads to the third floor.

The third floor consists of a small hall with doors to the balcony and a secret room containing the Big Mr. I. In the DS version, a Luigi painting that brings Mario to the Big Boo Battle stage is also present in the hall. To access the room with the Big Mr. I, the player has to be Vanish Mario or Vanish Luigi and enter through the large picture of a Boo before the power wears off. On the balcony lies the Big Boo and the player can Long Jump from the platform to access the roof.

The shed on the grounds of the mansion leads to an elevator that will bring the player to large halls when stepped on. At the end of the halls is a room with water and a Merry-Go-Round in the center, accessed by doors on either side. The Merry-Go-Round has a large spinning platform in the center and several portraits of Boos. One of the portraits has actual Boos come out of it and another acts like a fire jet.

Differences in the DS Version

 * In Super Mario 64 DS, the player can find King Boo, and although he is a large boo with a crown, he was still named "Big Boo" (even though the game was released after Luigi's Mansion).
 * At the top floor of the mansion, there is a Luigi painting that leads to the Big Boo Battle. Mario can access this by turning into Balloon Mario by hitting the Red ? Block, or by doing a wall kick. Luigi and Wario can back flip off the top of the ? Block.

Enemies

 * Boo
 * Big Boo
 * Mr. I
 * Big Mr. I
 * Mad Piano
 * Bookend
 * Scuttlebug
 * Killer Chair

Statistics from Super Mario 64

 * Total Number of coins: 151
 * Caps Found: Vanish Cap (3)
 * Spinning Heart: (none)
 * Cannons: (none)
 * 1-Up Mushrooms (2):
 * Static Mushroom : #1 On the top of the shed.
 * Box Mushroom : #2 On the top of the mansion.
 * Warps: (none)

Trivia

 * A remix of the Merry-Go-Round's theme is in Mario Strikers Charged as Boo's theme whenever he scores a goal.
 * It also is quite similar to Farewell to Gibdos from The Legend of Zelda: Majora's Mask.
 * The Merry-Go-Round music is also used near the Aqua Cups area in Mario Kart 8's Water Park.
 * The music for the Merry-Go-Round is also used in the minigames Lakitu Launch, Bingo Ball, and Slots Shot in Super Mario 64 DS and New Super Mario Bros.
 * When the star appears in the Merry-Go-Round after defeating the Big Boo, the Merry-Go-Round music will end and the standard mansion theme will play.
 * However, in the DS version, the music will still play, even after the merry-go-round stops spinning.
 * In Super Mario 64 DS and New Super Mario Bros., the minigame Hide and Boo Seek is set in the main lobby of the mansion.
 * This course has the most boss fights in the game. (Big Boo is fought three times, and Big Mr. I is fought once.)
 * In the DS remake, it is the only level with an entrance to [[Big Boo Battle|another level].
 * If the player activates first-person view when Mario is close enough to enter the course, the player can still move the camera for a bit before the screen transitions to the star select screen.
 * The mansion makes an appearance on Hole 2 of the Bowser Badlands in Mario Golf Toadstool Tour.
 * Big Boo's Haunt is the only course that does not share a theme with another course.