Big Al is the owner of the Carnival of Horrors from Escape from the Carnival of Horrors and it's sequel Return to the Carnival of Horrors. In both books, Big Al is the main antagonist and adversary that the reader must face.
Escape from the Carnival of Horrors
In this book, it is established that Big Al is the owner of the Carnival of Horrors, and he has the power to enslave carnival attendees, turning them into ghosts and keeping them in the Carnival of Horrors. It's unknown how old Big Al is or when he took control of the carnival.
Return to the Carnival of Horrors
In this book, the reader can visit Big Al's office. There, they find a control booth that has controls for basic things such as the rides, but it can also be used to control space and time. This allows Big Al to take the Carnival anywhere he wants.
Big Al is described as being hefty and abnormally tall. He has coal black eyes and a thick mustache. Furthermore, Big Al wears a bright checkered jacket.