The Creepy Steeple Boo

The Creepy Steeple Boo is obviously a Boo from Creepy Steeple in Paper Mario: The Thousand-Year Door. He is the Boo that asks Mario "How many Boos just came out?" after Mario frees the two hundred Boos from Creepy Steeple. It is unknown if he was actually a Boo that joined in to make Atomic Boo, as he is presumably a friendly character throughout the game and it is unknown if he was also reffering to himself when he asks how many Boos came out. Later in the game, he sends Mario an email saying that he is thankful for Mario freeing him and his friends.