Bug-A-Boo is referred to as "Bugaboo" on the dustjacket, but he is known only as the Monster in the Basement in this story. He is first called by name in Scary Godmother: Bloody Valentine #1 (Feb. 1998), which has both spellings; Scary Godmother - The Revenge of Jimmy (Sept. 1998) firmly established the spelling "Bug-A-Boo".
The "aschcan" preview Scary Godmother and Friends #[nn] was available at conventions earlier in 1997 than this hardcover; while not widely distributed, it features the actual first appearance of Scary Godmother, Hannah Marie, and other characters.