The Creepy Steeple Boo is first seen after Mario has opened a treasure chest that contained many Boos in it. The Creepy Steeple Boo then asks Mario a question on how many Boos were in the chest. If Mario guesses correctly (which is 200), The Creepy Steeple Boo gives Mario an Ultra Shroom. Later in the game, The Creepy Steeple Boo then sends Mario an email thanking him for freeing him and his friends earlier. He then tells Mario that there are treasures that might be still in the Creepy Steeple if he were to visit again.
- Oddly, The Creepy Steeple Boo is able to send an email normally despite being a ghost. Ghost T. had to take over the conductor in order to send Mario an email.
|Big Boo • Bigger Boo • Black Boo • Boolossus • Boos in Luigi's Mansion • Boos in Luigi's Mansion: Dark Moon • Bootler • Franky • Herbert • Igor • King Boo • King Boo (Super Mario Sunshine) • Lady Bow • Lahla • Peeka • Spooky Speedster • Stanley • The Creepy Steeple Boo|
|Balloon Boo • Big Boo • Big Boo (Paper Mario) • Big Frame Boo • Big & Little Boo • Blindfold Boo • Bomb Boo • Boo • Boo Balloon • Boo Block • Boo Buddy Snake • Boo Buddy Swarm • Boo Guy • Boohemoth • Boo Man Bluff • Boo Stack • Calm Fishin' Boo • Circling Boo Buddies • Dark Boo • Dark Dark Boo • Disappearing Boo Buddy • Eerie • Fishin' Boo • Frame Boo • Ghoul Guy • Gold Boo • Green Boo • Li'l Boo • Mad Big Boo • Mad Boo • Mini Boo • Octoboo • Peepa • Phantom Guy • Red Boo • Shiny Boo • Sleepy Boo • Snufit • Stretch • Tail Boo • Terekuribō|